property_type

property_type
name	parent	description
the name of the property	the name of the property of which this property is a subtype	a desription for the property
10_Minute_Gel_Strength	Shear_Stress	Shear Stress required to break a gel fluid previously allowed to remain at rest for 10 minutes.
10_Minute_Gel_Test_Deflection	Plane_Angle	The maximum reading (deflection) taken from a direct-reading viscometer after the fluid has been quiescent for 10 minutes.
10_Second_Gel_Strength	Shear_Stress	Shear Stress required to break a gel fluid previously allowed to remain at rest for 10 seconds.
10_Second_Gel_Test_Deflection	Plane_Angle	The maximum reading (deflection) taken from a direct-reading viscometer after the fluid has been quiescent for 10 seconds.
1_Minute_Gel_Strength	Shear_Stress	Shear Stress required to break a gel fluid previously allowed to remain at rest for 1 minute.
1_Minute_Gel_Test_Deflection	Plane_Angle	The maximum reading (deflection) taken from a direct-reading viscometer after the fluid has been quiescent for 1 minutes.
30_Minute_Gel_Strength	Shear_Stress	Shear Stress required to break a gel fluid previously allowed to remain at rest for 30 minutes.
30_Minute_Gel_Test_Deflection	Plane_Angle	The maximum reading (deflection) taken from a direct-reading viscometer after the fluid has been quiescent for 30 minutes.
API_Approx_Weight	Weight_Per_Joint	API approximate weight of one section
API_Code	Identifier	Code used by the API (American Petroleum Institute) to identify an industry related entity, e.g., Service Company, Country, another Standard organization, etc.
API_Country_Code	API_Code	Code used by the API (American Petroleum Institute) to identify sovereign nations, colonies, overseas territories, etc.
API_Design	Data_Valued_Property	The API design specification that the equipment meets
API_Entrance_Hole_Diameter	Perforation_Diameter	Entrance hole diameter in an API Section I test
API_Grade	Grade	Grade used by the API (American Petroleum Institute) to qualify material and/or equipment used in the industry, e.g., Tubulars.
API_Gravity	Density	A measure of hydrocarbon density equal to 141.5/(specific gravity @ 60 degF) - 131.5; usually reported with a temperature.
API_Neutron	Neutron_Porosity	The Neutron calibration measurement determined using the API test pit. This quantity is associated with the natural formation hydrogen concentration.
API_Nom_Weight	Weight_Per_Joint	API nominal weight of tube with joint for drill pipe and casing pipe
API_Pin_Conn_Size	Diameter	API pin connection size
API_Pin_Conn_Type	Type	API pin connection type
API_Plastic_Viscosity	Plastic_Viscosity	Measure of the internal resistance to fluid flow attributable to the amount, type, and size of solids present in a given fluid. When using the direct-indicating viscometer, it is found by subtracting the 300-rpm reading from the 600-rpm reading of a Fann35 rheometer.
API_Range	Length	API range characteristic for length of tubular goods
API_Reference	Publication_Title	The name of an API (American Petroleum Institute) reference, e.g., Bulletin D12A.
API_Total_Penetration	Perforation_Length	Total penetration in an API Section I test
API_Well_Number	Identifier	A unique well identification number as defined in the API (American Petroleum Institute) Bulletin D12A, as amended
API_Yield_Stress	Yield_Stress	Resistance to initial flow; the stress required to start fluid movement. When using the direct-indicating viscometer, it is found by subtracting plastic viscosity (API_Plastic_Viscosity) from the 300-rpm reading of a Fann35 rheometer.
ASAP_Depth_Parameter	Data_Valued_Property	Private structure used by the ASAP autotracking application; holds depth variations of time-domain Property ASAP_Parameter.
ASAP_Parameter	Data_Valued_Property	Private structure used by the ASAP autotracking application.
Abandon_Pressure	Pressure	The pressure at which a reservoir was or is expected to be abandoned.
Abandon_Time	Date	The time that a reservoir was or is anticipated to be abandoned.
Absolute_Abundance	Amount	Quantity of members in a group, as expressed as a count and count units, such as 5 sacks, 3 boxes, or 4 items.
Absolute_Delta_Flowrate	Flowrate	Absolute value of Delta Flow Rate. Calculated from the flowrate data contained in the Flow History, i.e., Q(associated Flow Period) - Q(previous Flow Period).
Absolute_Permeability	Permeability	The permeability of porous material when completely saturated with a wetting fluid and without the influence of non-Darcy (turbulence) effects. Also called "intrinsic" permeability.
Absolute_Permeability_Gas	Absolute_Permeability	The permeability of porous material when completely saturated with gas.
Absolute_Permeability_Oil	Absolute_Permeability	The permeability of porous material when completely saturated with oil.
Absolute_Permeability_Water	Absolute_Permeability	The permeability of porous material when completely saturated with water.
Absolute_Roughness	Rugosity	Average amplitude of rugosity, such as the variations in the radius of tubing.
Absolute_Time	Time	A time value which is intended to fix an event in time, such as a geological time, a date, or the start time of a process.
Acceleration	Data_Valued_Property	The rate of variation of velocity with time.
Accident_Type	Type	Type of Quality, Health, Safety, and Environmental accident such as Fluid Spill, Kick While Drilling, Kick While Tripping, ...
Accuracy	Statistical_Property	The extent to which a measurement approaches the true value of a quantity; usually expressed as a fraction of the true value or, for instrumentation, full scale.
Accuracy_Description	Description	Textual description of the data related to accuracy.
Acid_Concentration	Chemical_Concentration	Concentration of acid.
Acid_Treatment_Count	Count	Number of acid jobs
Acoustic_Amplitude	Amplitude	A measure of the maximum departure of an acoustic wave from the average value
Acoustic_Attenuation	Attenuation	The amount of reduction in the amplitude of an acoustic wave.
Acoustic_Attenuation_Rate	Attenuation_Rate	A measure of the rate of attenuation of an acoustic wave per unit length.
Acoustic_Caliper	Caliper	Borehole diameter as estimated by an acoustic logging device.
Acoustic_Contrast	Acoustic_Impedance	Interface property which is the difference between the Acoustic Impedance values of two adjacent beds.
Acoustic_Dispersion	Data_Valued_Property	Variation of acoustic velocity with frequency. Dispersion may be normal (velocity decreases with frequency) or inverse (velocity increases with frequency).
Acoustic_Energy	Energy	Energy of an acoustic wave, calculated as the sum of the squares of the amplitudes of the elements in a wavelet, sometimes multiplied by a proportionality constant.
Acoustic_Impedance	Data_Valued_Property	Property which controls the propagation of an ultrasonic wave in a medium. It is the product of the material density and the acoustic wave velocity within the material.
Acoustic_Impedance_Ratio	Ratio	Ratio of the acoustic impedance of two adjacent beds or intervals
Acoustic_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from an acoustic survey.
Acoustic_Slowness	Interval_Transit_Time	The time interval per unit length, Delta-T, necessary to attenuate a traveling acoustic wave. Applies to all types of Delta-T: Compressional, Shear and Stoneley.
Acoustic_Travel_Time	Time_Interval	The total time required for an acoustic wave to travel from one point to another.
Acoustic_Velocity	Velocity	The velocity of an acoustic wave which represents the rate at which the wave travels from one point to another. Used generally for all elastic and seismic waves.
Acquisition_Break_Time	Time_Interval	Acquisition system break time
Acquisition_Enable_Flag	Flag	Flag indicating whether or not acquisition is enabled for this activity.
Acquisition_File_Number	Ordinal_Number	Acquisition system file number
Acquisition_Rate	Frequency	Channel acquisition rate: number of data samples acquired per unit of time
Acquisition_Shot_Number	Ordinal_Number	Acquisition system shot number
Acquisition_Shot_Time	Time_Interval	Acquisition system shot time
Acquisition_Transit_Time	Transit_Time	Acquisition system transit time
Acquisition_Type	Type	Type or mode of data acquisition
Activation_Pressure	Pressure	Pressure at which recording should begin
Activation_Temperature	Temperature	Temperature at which recording should begin
Activity_Code	Code	The specific catalog-controlled code of an Activity performed on a Well, a Region, or an Earth subsurface component.
Activity_Name	Name	Commonly used name for an Activity.
Activity_Number	Identifier	External identifier assigned to an activity (e.g. job or proposal number).
Activity_Type	Type	The type of an Activity performed on a Well, a Region, or an Earth subsurface component, e.g. Drilling, Seismic, Logging, etc.
Address	Data_Valued_Property	The location where some entity or information may be found or contacted.
Adjustable_Choke_Flag	Flag	Flag indicating whether this flow period was performed on an adjustable choke, i.e., when set: adjustable choke, not set: fixed choke.
Admittance	Data_Valued_Property	The reciprocal of Impedance. The property of a medium to allow for the flow of an alternating current.
Adsorption	Data_Valued_Property	The adhesion in an extremely thin layer of molecules (as of gases, solutes, or liquids) to the surfaces of solid bodies or liquids with which they are in contact
Affine_Coeff_A	Coefficient	Coefficient "A" in an Affine transformation between two coordinate systems. The input and output coordinate systems may be local or projection systems.
Affine_Coeff_B	Coefficient	Coefficient "B" in an Affine transformation between two coordinate systems. The input and output coordinate systems may be local or projection systems.
Affine_Coeff_C	Coefficient	Coefficient "C" in an Affine transformation between two coordinate systems. The input and output coordinate systems may be local or projection systems.
Affine_Coeff_D	Coefficient	Coefficient "D" in an Affine transformation between two coordinate systems. The input and output coordinate systems may be local or projection systems.
Affine_Coeff_E	Coefficient	Coefficient "E" in an Affine transformation between two coordinate systems. The input and output coordinate systems may be local or projection systems.
Affine_Coeff_F	Coefficient	Coefficient "F" in an Affine transformation between two coordinate systems. The input and output coordinate systems may be local or projection systems.
Agency_Lease_Number	Identifier	Unique lease number assigned by leasing agency
Agreement_Interest	Proportion	Percentage of interest held by one of the potentially many organizations holding a lease agreement.
Agreement_Status	Status	Status of a lease agreement.
Air_Supply_Flowrate	Flowrate	The flowrate value which the air supply should be able to achieve
Air_Supply_Pressure	Pressure	Air supply pressure; for a burner, the pressure required to achieve effective atomization
Albite_Volume_Fraction	Volume_Fraction	The volume fraction of albite with respect to the total volume.
Alkalinity	Chemical_Concentration	Concentration of basic anions in an aqueous solution (e.g. OH-, CO3-- and HC03-)
Alkhalifah_Eta	Anisotropy	Alkhalifah's eta anisotropy parameter, describing the relationship between horizontal and moveout Compressional velocities.
Allowed_Position	Type	Allowed position of an equipment item with respect to the assembly in which it operates.
Alphacode	Code	Synonym of Code using the alphabet character set.
Alternate_Phone_Number	Phone_Number	Alternate phone number, including country code.
Altitude	Height	Height above a reference level, such as mean sea level.
Aluminum_Concentration	Concentration	Concentration of Aluminum by weight.
Aluminum_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of aluminum to total dry weight
Aluminum_Yield	Elemental_Yield	Elemental contribution of Aluminum with respect to total.
American_Aircraft_Regulation	Code	American Aircraft Transportation Regulation pertaining to a type of material or equipment, e.g., DOT-E-752 Cargo Only
Amount	Data_Valued_Property	Quantity, total number
Amount_Of_Substance	Amount	The amount of a particular substance (e.g. chemical) expressed in units of moles.
Amplitude	Data_Valued_Property	The extent or range of a property; especially, the maximum departure of a wave from its average value.
Amplitude_Correction	Correction	Amplitude correction applied to one side of an intersection
Amplitude_Difference	Amplitude	Amplitude difference between two interpretations. Usually, one interpretation is hand-picked and the other one snapped or smoothed (i.e. a slight modification of the first one).
Amplitude_Estimate	Amplitude	Amplitude value on one side of an intersection
Amplitude_Kurtosis	Kurtosis	Kurtosis of seismic amplitude (normalized).
Amplitude_Ratio	Ratio	Ratio of two amplitude values.
Amplitude_Skewness	Statistical_Skewness	Skewness of seismic amplitude (normalized).
Amplitude_Standard_Deviation	Standard_Deviation	Standard deviation of seismic amplitude.
Analytic_Trace	Acoustic_Amplitude	Complex seismic trace resulting from combination of input trace and its Hilbert transform. Normally represented as a pair of floating point numbers. [GeoFrame Value type: Complex32_t]
Anchor_Tension	Tension	Tension of the anchor chains or cables of a marine vessel; may be implemented as a vector.
Anelasticity_Factor	Coefficient	Factor used to compute loss of wave energy due to anelasticity (deviation from a linear proportionality between stress and strain). Loss is computed as exp(-pi * f * Anelasticity_Factor).
Angular_Acceleration	Data_Valued_Property	The rate of change of angular velocity per unit of time.
Angular_Dispersion	Data_Valued_Property	Variation of acoustic velocity with direction, distorting the shape of a wavetrain.
Angular_Velocity	Data_Valued_Property	Rotation rate, usually measured in revolutions per unit time; e.g., spinner speed, motor speed, etc. The term Angular Frequency is also used, but generally refers to data scaled in radians per second.
Anhydrite_Volume_Fraction	Volume_Fraction	The volume fraction of anhydrite with respect to the total volume.
Anisotropic_Axis_1_Crossline_Direction	Zenith_Angle	Angle of first (or only) anisotropic symmetry axis, relative to vertical, measured in the cross-line direction. Axis 1 on its own defines the rotational symmetry axis for transverse isotropy. If accompanied by Axis 2, they together define the symmetry planes for orthorhombic anisotropy.
Anisotropic_Axis_1_Inline_Direction	Zenith_Angle	Angle of first (or only) anisotropic symmetry axis, relative to vertical, measured in the in-line direction. Axis 1 on its own defines the rotational symmetry axis for transverse isotropy. If accompanied by Axis 2, they together define the symmetry planes for orthorhombic anisotropy.
Anisotropic_Axis_2_Crossline_Direction	Zenith_Angle	Angle of second anisotropic symmetry axis, relative to vertical, measured in the cross-line direction. Taken together with Axis 1, Axis 2 is used to define the symmetry planes for orthorhombic anisotropy.
Anisotropic_Axis_2_Inline_Direction	Zenith_Angle	Angle of second anisotropic symmetry axis, relative to vertical, measured in the in-line direction. Taken together with Axis 1, Axis 2 is used to define the symmetry planes for orthorhombic anisotropy.
Anisotropy	Data_Valued_Property	Measure of the variation of a property based upon the direction in which it is measured.
Annotation	Data_Valued_Property	Any annotation (or annotations) pertaining to an object. For example, annotations attached to a Map object.
Annual_Payment	Money	Annual amount of Payment based on some contractual agreement such as a lease. This could be rental, mortgage or other.
Annular_Pressure_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for an annular pressure measurement.
Annulus_Pressure	Pressure	Pressure of the fluid in the annulus. The annulus is the region outside the subject pipe, such as the region between drill pipe and the formation, or between casing and formation, or between tubing and casing.
Annulus_Volume	Volume	The volume of the portion of the borehole which lies between the borehole wall and the casing.
Anti_Collision_Method	Method_Type	Method used for calculating the proximity: 0 - Normal; 1 - Horizontal; 2 - Least Distance
Aperture	Width	The size of any opening in an otherwise solid wall or surface. The size of a window that limits the information affecting a measuring device. Also used in processing (e.g., seismic migration or deconvolution.)
Aperture_Time	Time_Interval	The time interval which contains the data used in a calculation, usually specified as the start and end times for the aperture.
Apparent	Modifier	Illusory, seeming, appearing as actual to the eye or mind.
Apparent_Dip_Angle	Dip_Angle	Angle between the dip plane and the plane perpendicular to the borehole
Apparent_Dip_Azimuth_North	Dip_Azimuth	In the plane perpendicular to the borehole, viewed from above the tool, angle measured clockwise from the projection of the north direction to the projection of the true dip azimuth.
Apparent_Dip_Azimuth_Tool	Dip_Azimuth	In the plane perpendicular to the borehole, viewed from above the tool, angle measured clockwise from logging tool reference direction to the projection of the true dip azimuth.
Apparent_Dip_Azimuth_Top_Of_Hole	Dip_Azimuth	In the plane perpendicular to the borehole, viewed from above the tool, angle measured clockwise from the top of hole direction to the projection of the true dip azimuth.
Apparent_Fluid_Velocity	Flow_Velocity	Apparent velocity of the fluid.
Apparent_Mud_Filtrate_Resistivity	Mud_Filtrate_Resistivity	Apparent resistivity of the mud filtrate, generally from log measurements of the "flushed zone".
Apparent_Porosity	Porosity	Initial estimate of porosity, normally from logs, not corrected for the (often large) effects of clays, gas, etc. Such estimates should only be used for qualitative interpretation of clean, gas-free intervals.
Apparent_Seismic_Polarity	Analytic_Trace	Sign of trace sample scaled with Reflection_Strength; used for seismic displays.
Apparent_Thickness	Thickness	Layer thickness measurement along the borehole, neither corrected for borehole deviation nor for layer dips
Apparent_Velocity	Acoustic_Velocity	In seismics, the phase velocity which a wavefront appears to have along a line of geophones. Otherwise, the inverse of the slope of a refraction time-distance curve.
Apparent_Viscosity	Viscosity	Ratio Shear Stress/Shear Rate. Equal to Newtonian Viscosity for Newtonian fluid.
Apparent_Water_Resistivity	Water_Resistivity	Apparent resistivity of connate (formation) water, generally from logs; such estimates require correction before they can be used quantitatively.
Arc_Type	Type	The type of Arc objects which bound surface regions of the Earth, e.g. State Boundary, River, etc.
Archie_Porosity_Constant	Exponent	The constant "a" in the Archie formation resistivity factor - porosity relationship.
Archie_Porosity_Exponent	Exponent	The exponent of the Porosity term in the Archie formation resistivity factor - porosity relationship. Abbreviated "m".
Array_Code	Code	Catalog-controlled code of an Array
Array_Conductivity	Conductivity	Formation conductivity as measured by a device capable of taking measurements at various combinations of resolution, depth of investigation, azimuth; such surveys allow detailed investigation of the invasion profile.
Array_Induction_Conductivity	Array_Conductivity	Formation conductivity as measured by an induction device capable of taking measurements at various combinations of resolution, depth of investigation, azimuth; such surveys allow detailed investigation of the invasion profile.
Array_Induction_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from an array induction survey.
Array_Induction_Resistivity	Array_Resistivity	Array Resistivity measurement using induction logging principles.
Array_Laterolog_Conductivity	Array_Conductivity	Formation conductivity as measured by a laterolog device capable of taking measurements at various combinations of resolution, depth of investigation, azimuth; such surveys allow detailed investigation of the invasion profile.
Array_Laterolog_Resistivity	Array_Resistivity	Array Resistivity measurement using laterolog (or guard log) resistivity logging principles.
Array_Resistivity	Resistivity	Formation resistivity as measured by a device capable of taking measurements of at various combinations of resolution, depth of investigation and/or in different azimuthal directions.
Article_Title	Publication_Title	Title of article or memo
Ash_Volume_Fraction	Volume_Fraction	The volume fraction of ash with respect to the total volume.
Aspect_Ratio	Shape	Ratio of width to length. Also the ratio of vertical to horizontal scales on a graph, or that of the shorter to longer axes for an ellipse or ellipsoid.
Atomic_Number	Data_Valued_Property	An experimentally determined number characteristic of a chemical element that represents the number of protons in the nucleus which in a neutral atom equals the number of electrons outside of the nucleus and that determines the place of the element in the periodic table.
Atomic_Weight	Data_Valued_Property	The average relative weight of an element referred to some element taken as a standard; basis may be hydrogen with an atomic weight of 1, oxygen with an atomic weight of 16, or carbon with an atomic weight of 12.
Attenuation	Data_Valued_Property	Loss in energy or reduction in sensitivity. In seismic work, loss in acoustic energy due to absorption, reflection, etc. which occurs between any two points of travel.
Attenuation_Factor	Indicator	Coefficient used to quantify the attenuation of a plane wave: a wave traveling a distance X will be reduced by a factor of e**(-AX), where A is attenuation factor.
Attenuation_Gain	Data_Valued_Property	Change in electric potential per unit of attenuation, where attenuation is generally expressed in dB.
Attenuation_Rate	Data_Valued_Property	A measure of the rate of attenuation of a wave per unit length.
Attenuation_Resistivity	Electromagnetic_Propagation_Resistivity	Formation resistivity as measured by the attenuation of a high frequency (hundreds of KHz to several MHz) electromagnetic wave; these measurements are typically deeper than measurements based on phase shift, but their vertical resolution is less sharp and they often cannot be used reliably in high-resistivity formations.
Attribute_Name	Name	Name of an Attribute of an Object
Author_Name	Person_Name	Author of document
Authorization_For_Expenditure	Identifier	Identifier of granted or candidate request for authorization to spend money, usually for a specified purpose and amount. Abbreviated AFE
Auto_Exit	Processing_Option	Flag indicates module is to be automatically stopped when run in chain
Auto_Start	Processing_Option	Flag indicates module is to be automatically started when run in chain
Availability	Type	An indicator of the degree to which data, a product or a service is available for use; used to classify E&P data in order to support filtering of non-essential data from output.
Average	Modifier	The data related to the property is the average of two or more other data sources.
Averaging_Interval	Interval_Length	Length of interval over which data are averaged.
Avg_Acoustic_Velocity	Acoustic_Velocity	Average velocity of an acoustic wave: the distance between two points divided by the travel time of the compressional wave between those points.
Avg_Amplitude	Amplitude	Average (mean) value of amplitude.
Avg_Bed_Thickness	Thickness	Average thickness of a geologic bed.
Avg_Compressional_Shear_Velocity_Ratio	Compressional_Shear_Velocity_Ratio	Time average of compressional-shear velocity ratio from top to reflector.
Avg_Density	Density	Average value of the material density.
Avg_Flowrate	Flowrate	Average Flowrate on a given period of time
Avg_Magnitude	Magnitude	Average (mean) magnitude.
Avg_Mode_Converted_Velocity	Mode_Converted_Velocity	Average converted-wave velocity from the surface to the reflector. The converted wave velocity is determined from the time taken for the energy to travel in one direction as compressional wave and in the other as shear.
Avg_Peak_Amplitude	Amplitude	Average of the amplitudes of waveform peaks.
Avg_Penetration_Rate	Penetration_Rate	Average drilling penetration rate (ROP)
Avg_Porosity	Porosity	Average value of the material Porosity.
Avg_Pressure	Pressure	Pressure averaged on a given time.
Avg_Q_Ratio	Q_Ratio	Average (harmonic mean) value of the compressional wave quality factor.
Avg_Qs_Ratio	Qs_Ratio	Average (harmonic mean) value of the shear wave quality factor.
Avg_Reservoir_Pressure	Pressure	The average pressure (somewhere in the reservoir) between the borehole pressure and external boundary pressure.
Avg_Running_Speed	Running_Speed	Average Speed of equipment running into (counted positive) or out of the hole (counted negative).
Avg_Seismic_Energy	Acoustic_Energy	Energy of seismic trace within window, computed by summing the squares of the amplitude values and dividing by the number of samples summed.
Avg_Seismic_Velocity	Avg_Acoustic_Velocity	Special usage of Avg_Acoustic_Velocity which deals specifically with the velocity between a reference datum near the surface and some subsurface point; often a vertical path is implied and the velocity is computed as depth divided by seismic travel time.
Avg_Sequence_Trend	Coefficient	A coefficient that characterizes the upwards or downwards increasing conductivity trend within a given depth interval
Avg_Shear_Compressional_Velocity_Ratio	Shear_Compressional_Velocity_Ratio	Time average of shear-compressional velocity ratio from top to reflector.
Avg_Shear_Velocity	Shear_Velocity	Average shear wave velocity, from the surface to the reflector. The shear wave velocity is determined from the two-way vertical time taken for the energy to travel to the reflector and back as a Shear wave.
Avg_Trough_Amplitude	Amplitude	Average of the amplitudes of waveform troughs.
Avg_Weight_On_Bit	Weight_On_Bit	Average "Weight On Bit" (WOB)
Award_Date	Date	Date lease awarded
Axial_Length	Length	The length associated with the longest dimension of an object. This corresponds to the height of a cylinder, or the longest axis of a rectangle.
Axial_Spacing	Length	The spacing or distance between two locations on an equipment item; for example, between two sensors on a logging tool.
Axis_Azimuth	Azimuth	Azimuth of the axis, usually pertaining to a depositional environment such as a tidal-flat.
Axis_First_Value	Multi_Use_Property	First value along axis
Axis_Index_Code	Code	Code of axis of n-dimensional data array.
Axis_Spacing	Multi_Use_Property	Spacing or displacement along axis
Axis_Unit	Unit_Code	Unit for spacing and start value on axis.
Azimuth	Plane_Angle	Horizontal angle measured clockwise from true North. (Also referred to as True Bearing.) Occasionally azimuth will be specified relative to some other reference.
Azimuth_Error	Error	Plus or minus azimuth error of sensor
Azimuth_Reference_Type	Type	Type of geographical object used as reference for azimuth measurements: by default, azimuths are referred to True North.
Azimuth_Turn_Rate	Curvature	The rate of change of the azimuth of the borehole, normally expressed in degrees per unit of course length
Azimuth_Unit	Unit_Code	Unit for Azimuth data
BHA_Number	Identifier	An identification number assigned to a bottomhole assembly, normally for tracking purposes at the wellsite.
BHA_Run_Number	Run_Number	Sequence number of the bottomhole assembly (BHA) run.
Back_Pressure_Drop	Pressure	Constant pressure drop on a flowline used mainly to approximate any kind of restriction, choke, nozzle ...
Background_Pressure_Trend	Pressure	Background pressure trend for a horizontal interference test
Bad_Hole_Flag	Flag	Flag indicating that the hole is in poor condition (e.g. oversize or overly rugose)
Bale_Kappa	Anisotropy	Bale's kappa, the mode-converted wave equivalent to eta, describing the relationship between horizontal and moveout mode-converted wave velocities.
Bale_Xi	Anisotropy	Bale's xi, the shear wave equivalent to eta, describing the relationship between horizontal and moveout shear wave velocities.
Band_High_Frequency	Frequency	Upper limit of frequency band (range)
Band_Low_Frequency	Frequency	Lower limit of frequency band (range)
Bandwidth	Data_Valued_Property	Effective frequency range, typically between the half-power points (the frequencies at which the power drops to half of the peak power). Bandwidth is occasionally represented by the central frequency of the band or as the difference between the lower and upper limits of the frequency band, but generally the absolute frequencies should be specified, such as by using Band_Low/High_Frequency properties or by using a complex value type with the Bandwidth property.
Bandwidth_Rating_Bias	Bandwidth	Statistical estimation of bandwidth of data within window. Aids in determining appropriate spectral operators for subsequent operations. Computation: Let the autocorrelation of the trace be A[i]. Then compute M = max(A) and S = sum(A[i]2). The bandwidth rating bias B is then : B = M2 / r(2 S - M**2), where r is the sample rate.
Bandwidth_Rating_Bias_Wavenumber	Wavenumber	Bandwidth rating bias in depth domain. See Bandwidth_Rating_Bias
Bandwidth_Rating_Debias	Bandwidth	Statistical estimation of bandwidth of data within window. The bandwidth rating debias D is computed from the bandwidth rating bias B as follows: D = 5/3 B - 1/(s*n), where n is the number of sampled used in the computation. Generally more stable than Bandwidth_Rating_Bias, unless window is small.
Bandwidth_Rating_Debias_Wavenumber	Wavenumber	Bandwidth rating debias in depth domain. See Bandwidth_Rating_Debias
Barium_Yield	Elemental_Yield	Elemental contribution of Barium with respect to total.
Barometric_Pressure	Pressure	The pressure of the atmosphere(relative to vacuum) as measured by a Barometer
Base_Fluid_Type	Fluid_Type	The type of the base fluid usually used in chemical mixing, such Oil or Water.
Base_For_Spacing	Processing_Option	A flag that determines which reference along a Borehole will be used to space Boreholes on a Cross Section.
Base_Latitude	Latitude	Latitude value used as the basis or starting point, such as in a multiple regression computation.
Base_Longitude	Longitude	Longitude value used as the basis or starting point, such as in a multiple regression computation.
Baselap_Type	Type	The type of a Baselap in the Earth subsurface, whether it is an Onlap or a Downlap
Battery_Code	Code	Code for the recorder battery
Battery_Life	Time_Interval	Battery Life
Battery_Type	Type	Recorder battery type
Battery_Weight	Weight	Battery Weight
Baud_Rate	Frequency	The net speed at which data are transmitted.
Bearing	Plane_Angle	The horizontal angle between the direction to a point and the direction of some reference line, normally measured as a clockwise angle from the reference line.
Bearing_Type	Type	Type of bearing, such as sealed or mud lubricated
Beaufort_Scale_Number	Wind_Velocity	The Beaufort wind scale is a system used to estimate and report wind speeds when no measuring apparatus is available. It was invented in the early 19th century by Admiral Sir Francis Beaufort of the British Navy as a way to interpret winds from conditions at sea, e.g. 5 on the Beaufort scale corresponds to a wind of 17-21 knots and is defined as "Fresh Breeze: Moderate waves (1.8m), many white horses."
Bed_Character	Type	The Characteristic given to a Bed or layer (e.g. has sealing characteristic or is probable source rock.)
Bed_Set_Type	Type	The type of bed grouping
Bed_Type	Type	The general physical and structural character or pattern of beds and their contacts within a rock mass; e.g., cross-bedding and graded bedding; homogenous, wave ripples, planar cross beds.
Begin_Element	Ordinal_Number	The number of the first element, usually in an array or along an axis.
Begin_Time	Absolute_Time	Time at which a process began
Bend_1_Angle	Plane_Angle	Angle of first bend in equipment item.
Bend_1_Bend_2_Angle	Plane_Angle	Angle between the planes defined by the first and second bends in the equipment string.
Bend_1_To_Bottom_Conn	Length	Length from the first bend to the bottom connection of the tool
Bend_2_Angle	Plane_Angle	Angle of second bend in equipment item.
Bend_2_Bend_3_Angle	Plane_Angle	Angle between the planes defined by the second and third bends in the equipment string.
Bend_2_To_Bottom_Conn	Length	Length from the second bend to the bottom connection of the tool
Bending_Moment_Per_Length	Data_Valued_Property	For a rotating body, the product of force and length of angular displacement normalized for the radius of rotation.
Bid_Amount	Money	Amount of lease bid
Bid_Number	Identifier	Bid number assigned by governing agency
Bin_Porosity	Apparent_Porosity	Contribution of porosity from a given "bin" (with certain characteristics) to the total porosity; e.g., in nuclear magnetic resonance data processing, the "bins" typically correspond to different pore size ranges.
Biological_Name	Name	A name used for classifying items in a biological taxonomy.
Biot_Coefficient	Coefficient	The proportion of fluid pressure in a material which acts to counterbalance overburden pressure. Used in the calculation of net overburden: P_eff = P_overburden - (Biot_Coefficient * P_fluid).
Biotite_Volume_Fraction	Volume_Fraction	The volume fraction of biotite with respect to the total volume.
Bioturbation_Type	Type	The type of Bioturbation: the mixing of sediments by burrowing organisms.
Bit_Bladed_Flag	Flag	Flag indicating that the bit is a bladed type (PDC type bit).
Bit_Depth	Depth	Depth of the drillbit
Bit_Inclination	Hole_Deviation	Inclination of the drillstring as measured as the bit
Bit_Number	Identifier	An identification number assigned to a drill bit, normally for tracking purposes at the wellsite.
Bit_Operating_Time	Operating_Time	Operating time of the bit over the reporting period.
Bit_Profile	Type	Profile of the bit (PDC type bit)
Bit_Rate	Frequency	The number of bits that may be transported, say via telemetry, per unit time.
Bit_Rotation_Speed	Angular_Velocity	Rotational speed of the Drill Bit
Bit_Run_Number	Run_Number	Sequence number of the bit run.
Blade_Gauge_Length	Length	Length of the in-gauge portion of the blade.
Blade_Height	Length	Height of blade at gauge from the body of the equipment, such as a stabilizer.
Blade_Length	Length	Length of blade measured along spiral; used for drill stabilizer blades.
Blade_Material	Material_Type	Material used in the blade, such as steel, aluminum or plastic. This material represents material of sleeve structure in sleeve type stabilizers and is the same as the body material in integral stabilizers.
Blade_Spiral	Plane_Angle	Degree of spiral blade coverage 0, 270, 450, -270. (0-straight blade; Negative-left spiral; Positive-right spiral)
Blade_To_Conn_2	Length	Distance from blade to Connection 2.
Blade_Width	Width	Width of the blade at gauge, as used for drill stabilizer blades.
Bladeface	Plane_Angle	In directional drilling, the angle between a (sensor-bearing) stabilizer blade and a fixed reference, measured in a plane normal to the drillstring. In near-vertical applications, North is the fixed reference (Magnetic_Bladeface); for higher deviation applications, Top of Hole is the reference (Gravity_Bladeface).
Blocking_Method_Type	Method_Type	Blocking method
Boat_Type	Type	Supply boat, tanker, dynamic positioning vehicle etc.
Bob_Number	Ordinal_Number	Bob number. The bob is the inner cylinder of a cylindrical rheometer. Each number corresponds to a different size. Standard bob is #1
Body_Material	Material_Code	Material used in the body such as steel, aluminum, monel
Boiling_Point	Temperature	The temperature at which fractions of a liquid boil.
Bore_Count	Count	Number of bores, as in a production packer.
Bore_Inside_Diameter	Inside_Diameter	The inside diameter of the equipment bore.
Bored_Flag	Flag	Flag to indicate that equipment item has been bored.
Borehole_Diameter	Inside_Diameter	The inside diameter of a borehole.
Borehole_Neutron_Capture_Cross_Section	Neutron_Capture_Cross_Section	The macroscopic neutron capture cross section, i.e. the effective cross sectional area per unit volume, of the borehole environment; used to correct "Sigma" log measurements for borehole effects.
Borehole_Radius	Radius	Radius of the open borehole. Normally taken as the radius of the drillbit.
Borehole_Salinity	Salinity	Salinity of the fluid in the borehole.
Borehole_Status	Status	A property indicating current status of a Borehole: Producing, Abandoned, etc. Related to the Petroleum Information (PI) codes.
Borehole_Temperature	Fluid_Temperature	Temperature of the material in the borehole.
Borehole_Volume	Volume	The volume of the borehole.
Boron_Yield	Elemental_Yield	Elemental contribution of Boron with respect to total.
Bottom_Depth	Depth	The deepest depth of a borehole interval, a formation, or any depth indexed representation of a data item.
Bottom_Dip_Number	Dip_Number	Number of Dip (in the Dip Set) at the bottom of the Bed
Bottom_Discontinuity_Type	Discontinuity_Type	Type of Discontinuity forming the bottom boundary.
Bottom_Location	Location	The location of the Bottom of any Entity with a geometric extent (e.g., Zone Interval, Borehole, Borehole Segment, Rig, Arc, Edge, etc.). It is represented by some position relative to a coordinate system.
Bottom_Subsea_Vertical_Depth	Subsea_Vertical_Depth	Subsea Vertical Depth of Bottom of Interval
Bottom_True_Stratigraphic_Thickness_Depth	True_Stratigraphic_Thickness_Depth	True Stratigraphic Thickness Depth of Bottom of Interval
Bottom_True_Vertical_Depth	True_Vertical_Depth	True Vertical Depth of Bottom of Interval
Bottom_True_Vertical_Thickness_Depth	True_Vertical_Thickness_Depth	True Vertical Thickness Depth of Bottom of Interval
Bottom_Two_Way_Time	Two_Way_Time	Depth of Bottom of Interval in Two Way Time
Bottom_Value	Multi_Use_Property	Value at the bottom of an interval.
Bottom_Vertical_Section	Vertical_Section	Bottom "depth" of an interval along a Vertical Section (VSCT) index.
Bottomhole_Circulating_Pressure	Bottomhole_Pressure	The pressure at the bottom of a borehole during circulation of any fluid.
Bottomhole_Circulating_Temperature	Bottomhole_Temperature	The bottom hole temperature reached when circulating. Due to the cooling effect of the drill fluid, BHCT is below the BHST.
Bottomhole_End_Type	Type	Indicates what limits the total depth (plug back, borehole bottom, bridge plug, sump packer ...)
Bottomhole_Flowing_Pressure	Bottomhole_Pressure	Flowing pressure inside the wellbore at midpoint of the completed interval. Res. Eng. Pwf
Bottomhole_Flowing_Temperature	Bottomhole_Temperature	Temperature at the bottom of the well while flowing.
Bottomhole_Mud_Resistivity	Mud_Resistivity	Resistivity of the mud at Bottomhole Conditions
Bottomhole_Pressure	Pressure	The pressure at the bottom of a borehole generally associated with the pore pressure of the formation open to the well.
Bottomhole_Shutin_Pressure	Bottomhole_Pressure	The pressure at the bottom of a borehole with the well shut in.
Bottomhole_Static_Temperature	Bottomhole_Temperature	The bottom hole equilibrium temperature (when circulation is stopped)
Bottomhole_Temperature	Temperature	The temperature at the bottom of a borehole occurring at the time of the activity being performed on the well.
Bound_Water_Conductivity	Conductivity	Conductivity of water bound to clay in the formations.
Bound_Water_Resistivity	Resistivity	Resistivity of water bound to clay in the formations.
Bound_Water_Saturation	Saturation	The extent to which the pore space in a formation contains bound water.
Bound_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of bound Water with respect to the total volume.
Boundary_File	File_Name	Name of file containing boundaries
Boundary_Type	Type	The type of a Boundary in the Earth subsurface, e.g. Facies Boundary, Sequence Boundary, etc.
Bowl_Speed	Centrifuge_Speed	The bowl speed of a centrifuge.
Box_Number	Identifier	Number of box in which an item or sample is stored.
Breakdown_Pressure	Pressure	The pressure required to create a hydraulic fracture in an unfractured formation; it is greater than fracture closure pressure except in rare cases, such as very low fracture toughness and very large horizontal stress anisotropy.
Bubble_Flow_Velocity	Flow_Velocity	The rate at which a fluid bubble, gas or liquid, flows through another fluid, gas or liquid. The Velocity depends on the densities and viscosities of the fluids.
Bubble_Point_Pressure	Pressure	The pressure at reservoir temperature at which gas in solution in crude oil comes out of solution as free gas.
Bubble_Point_Temperature	Temperature	The temperature at reservoir conditions at which gas in solution in crude oil comes out of solution as free gas.
Bubble_Size	Diameter	Diameter of the bubbles of non-continuous production phase.
Buildup_Pressure	Pressure	Pressure recorded in the borehole at downhole conditions during a pressure buildup test.
Bulk_Addition_Mode	Type	Describes how the bulk material was added to the mixture.
Bulk_Density	Density	Density of bulk material, including any void space or other materials contained in the subject volume. In well logging, it is the density of the rock, including fluid-filled pore space, as measured with a "Gamma-Gamma" type logging device.
Bulk_Density_Correction	Correction	Correction to the Bulk Density log, as measured with a Gamma-gamma type logging device; used as an indication of hole condition to validate the Bulk_Density measurement; conventionally abbreviated DRHO.
Bulk_Modulus	Elastic_Modulus	The stress-strain ratio under simple hydrostatic pressure. k = Delta-P / (Delta V / V), where Delta-P, -V denote the change in Pressure and Volume.
Burner_Code	Code	Code for burner equipment
Burner_Head_Count	Count	Number of heads of the burner (conventionally, 3,4 or 6)
Burner_Pilot_Pipe_Size	Diameter	Standard gas pipe size connection supplied on the pilot inlet equipment
Burner_Type	Type	Type of burner
Burst_Pressure	Pressure	Burst Pressure.
Business_Associate_Job_Title	Type	The assignment of an administrative job title to a business associate in the context of a business association
Business_Line	Data_Valued_Property	Group of activities or services gathered by some commonalities
Business_Line_Code	Code	MIS Code of the business line
Business_Region_Type	Type	The type of a Business defined region of the Earth surface, e.g. Field, Lease, Concession, etc.
Byte_Count	Count	Total number of bytes used or required by a collection of data.
C2H6_Concentration	Chemical_Concentration	Concentration of C2H6 by volume. Typical value in natural gas 6%.
C3H8_Concentration	Chemical_Concentration	Concentration of Propane (C3H8); typical volume concentration in natural gas is 2%.
C4H10_Concentration	Chemical_Concentration	Concentration of Butane (C4H10).
C5H12_Concentration	Chemical_Concentration	Concentration of Pentane (n-C5H12).
C6H14_Concentration	Chemical_Concentration	Concentration of Hexane (C6H14); typical volume concentration in natural gas is 0.3%.
C7H16_Concentration	Chemical_Concentration	Concentration of Heptane (C7H16)
C7plus_Concentration	Chemical_Concentration	Concentration of Heptane and hydrocarbons heavier than Heptane; typical volume concentration in natural gas is 0.5%
C7plus_Plus_Molecular_Weight	Molecular_Weight	Molecular weight of Heptane (C7H14) and heavier component concentration in crude oil. Typical value: 110-130
C7plus_Specific_Gravity	Specific_Gravity	Specific Gravity versus air at standard conditions of the Heptane (C7H14) and heavier component found in crude oil
CBL_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from a Cement Bond logging survey.
CCP_Trajectory	Trajectory	List linking shots and receivers to Common Conversion Points (CCP) in depth. Defines the trajectory in shot-offset domain to stack along to image a point in depth.
CH4_Concentration	Chemical_Concentration	Concentration of Methane (CH4); typical volume concentration in natural gas is 85%.
CO2_Concentration	Chemical_Concentration	Concentration of Carbon Dioxide (CO2)
CO2_Foam_Quality	Ratio	Ratio volume of CO2 over foam volume. Indicator of the quality of a foam generated with CO2 for well treatment. Below 50% the foam is not stable, above 95% the foam changes to a mist. C02 foam are used when low pH is required.
CO2_Mole_Fraction	Mole_Fraction	Mole fraction of Carbon Dioxide to total gas composition
CO_Concentration	Chemical_Concentration	Concentration of Carbon Monoxide (CO)
CS_Trans_Type	Type	The type of Transformation used between 2 coordinate systems, e.g. Molodensky, Affine 2D, etc.
CaCl2_Concentration	Chemical_Concentration	CaCl2 concentration.
Cable_Length	Length	Cable length; measured from a fixed reference point and used as Measured Depth in Wireline operations
Cable_Speed	Velocity	Cable speed, generally measured at the surface as an approximation of tool speed.
Cable_Type	Type	Type of cable.
Calcite_Volume_Fraction	Volume_Fraction	The volume fraction of calcite with respect to the total volume.
Calcium_Concentration	Chemical_Concentration	Calcium concentration (Water Based Mud and water phase for Oil Based Mud)
Calcium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of calcium to total dry weight
Calcium_Yield	Elemental_Yield	Elemental contribution of Calcium with respect to total.
Calibrated	Modifier	A calibration process has been applied to the data related to the property.
Calibration_Coefficient_Code	Code	Calibration coefficient code.
Calibration_Date	Date	Date of calibration for the equipment; time may also be included.
Calibrator_Type	Type	Type of device used to calibrate the sensor or tool.
Caliper	Borehole_Diameter	Borehole diameter as measured by a logging device: a record of the borehole or the internal diameter of tubular goods.
Capacitance	Data_Valued_Property	The ratio of the charge on a capacitor to the electric potential across it.
Capacitive_Reactance	Reactance	The component of electrical impedance due to capacitance: Xc = 1 /(2 pi F C), where F is the frequency and C is the capacitance.
Capillary_Number	Ratio	The ratio of capillary to viscous forces on fluids in a porous media.
Capillary_Pressure	Pressure	The difference in pressure between two phases, air fluid, gas fluid or between two fluids, measured at points of the interconnected phases.
Capillary_Pressure_Function	Function_Name	Name of the function used to represent capillary pressure.
Capillary_Pressure_Function_Coeff	Coefficient	Coefficients used in the capillary pressure function.
Capillary_Transition_Zone_Height	Height	The vertical interval height that describes the transition between two different fluid phases in a porous media. This transition is caused by changes in saturation dependent capillary forces in equilibrium with gravitational forces.
Carbon_Oxygen_Ratio	Ratio	Ratio of relative abundance of Carbon to that of Oxygen; important for hydrocarbon detection and saturation determination because it is independent of salinity.
Carbon_Volume_Fraction	Volume_Fraction	The volume fraction of carbon with respect to the total volume.
Carbon_Yield	Elemental_Yield	Elemental contribution of Carbon with respect to total.
Carbonate_Volume_Fraction	Volume_Fraction	The volume fraction of carbonate rock with respect to the total volume.
Cardinality	Count	Number of instances of an Entity type which may be referred to by another Entity in a particular relationship; may be ONE or MANY.
Casing_Collar_Locator	Indicator	Signal from a device which indicates the presence of a casing or tubing collar, used for depth control in logging operations.
Casing_Grade	Steel_Grade	Casing pipe grades given to material properties that fall within the tolerances set by API specifications; e.g., J55, K55, H40, etc.
Casing_Inside_Diameter	Inside_Diameter	Casing inner diameter
Casing_Outside_Diameter	Outside_Diameter	Casing outer diameter
Casing_Rotation_Friction_Coefficient	Friction_Coefficient	Friction coefficient due to rotation between casing and other surface (e.g. drill string).
Casing_Shoe_Depth	Depth	Casing shoe depth
Casing_Sliding_Friction_Coefficient	Friction_Coefficient	Friction coefficient due to sliding between casing and other surface (e.g. drill string), when only sliding motion is present
Casing_Translation_Friction_Coefficient	Friction_Coefficient	Linear component of the friction coefficient between casing and drill string during an helical movement, e.g., reaming mode
Casing_Type	Type	Type of casing or tubing used, such as riser, conductor, intermediate, liner, surface, tubing, production, etc.
Casson_Plastic_Viscosity	Plastic_Viscosity	Measure of the internal resistance to fluid flow attributable to the amount, type, and size of solids present in a given fluid. The Casson model equation is: SQRT(Shear_Stress) = SQRT(Yield_Stress) + SQRT(Plastic_Viscosity X Shear_Rate)
Casson_Yield_Stress	Yield_Stress	Resistance to initial flow; the stress required to start fluid movement. The Casson model equation is: SQRT(Shear_Stress) = SQRT(Yield_Stress) + SQRT(Plastic_Viscosity X Shear_Rate)
Catalog_Code	Entity_Code	Code of the catalog entity providing further specifications of the leaf entities of a certain entity type.
Cation_Concentration	Chemical_Concentration	The concentration of cations, the positively charged particles, in the solution of an electrolyte.
Cation_Exchange_Capacity	Data_Valued_Property	A measure of the extent to which a substance will supply exchange cations.
Cell_Count	Count	Number of cells
Cement_Additive_Type	Type	Type of additive(s) used to change the properties of the cement.
Cement_Bond_Amplitude	Acoustic_Amplitude	A measure of acoustic wave amplitude used for cement bond evaluation.
Cement_Bond_Index	Indicator	The ratio of acoustic wave attenuation in a zone of interest to that measured in a well-cemented section of casing, used as an indication of the quality of a casing cement job.
Cement_Density	Density	The density or weight per unit volume of cement (or cement slurry).
Cement_Retarder_Type	Type	Type of material used to retard the setting of the cement.
Cement_Sheath_Thickness	Thickness	Thickness of the cement sheath between casing and borehole wall.
Cement_Type	Type	Type of cement
Cement_Unit_Discharge_Pressure	Pressure	Cementing unit maximum discharge pressure
Cement_Unit_Output	Flowrate	Cementing unit maximum output flowrate
Cement_Unit_Power	Hydraulic_Power	Cementing unit input horse power
Cement_Unit_Type	Type	Cementing unit type
Cement_Volume	Volume	Volume of cement.
Cementitious_Flag	Flag	Flag indicating if the chemical is accounted for as a cement when proportioning by weight of blend. Cementitious chemicals are mostly weight extenders like bentonite.
Central	Modifier	Containing or constituting a center.
Central_Frequency	Frequency	Central frequency within power spectrum; average of the low and high frequencies of the band.
Central_Line_Bearing	Azimuth	Azimuth of central line of projection.
Central_Line_Pt1_Latitude	Latitude	Latitude of first point on central line of projection.
Central_Line_Pt1_Longitude	Longitude	Longitude of first point on central line of projection.
Central_Line_Pt2_Latitude	Latitude	Latitude of second point on central line of projection.
Central_Line_Pt2_Longitude	Longitude	Longitude of second point on central line of projection.
Central_Line_X_Alignment	Flag	Alignment of central line x-coordinate: 0 if central line is x-axis, 1 if x-axis is east west
Central_Meridian	Longitude	The meridian on a graticule that is the axis of symmetry for the geometric properties of the graticule displayed on a map projection.
Central_Wavenumber	Wavenumber	Central frequency in the depth domain
Centralizer_Code	Code	Centralizer Code
Centralizer_Count_Per_Joint	Count	Number of centralizers per joint, e.g. 2 per joint.
Centralizer_Outside_Diameter	Outside_Diameter	Centralizer outside diameter
Centralizer_Test_Type	Type	The type of a Centralizer Test used to test a centralizer, usually during any well operation.
Centralizer_Type	Type	The type of a Centralizer used to center a casing, a tubular, or a logging tool in the center or near the center of the borehole, aligned with the borehole axis.
Centrifuge_Speed	Angular_Velocity	The bowl speed of a centrifuge.
Cesium_Concentration	Concentration	Concentration of Cesium.
Channel_Width	Width	The perpendicular distance between two parallel boundaries.
Chemical_Concentration	Concentration	The concentration of a chemical usually used during well operations, like drilling, cementing, acidizing, fracturing, etc.
Chemical_Formula	Formula	A symbolic expression of the composition or constitution of a substance.
Chemical_Function	Type	Primary purpose of a chemical e.g. Corrosion_Inhibitor, Gelling_Agent, Retarder, Emulsifier, ...
Chemical_Product_Type	Type	The type of a Chemical Product used in various types of activities, usually those provided by Dowell-Schlumberger
Chemistry_Type	Type	Type of chemical system.
Chi_Square	Statistical_Property	Statistical test of data distribution, used to measure goodness of fit of the data to some distribution model.
Chloride_Concentration	Chemical_Concentration	Concentration of chloride ions in water based mud or in the water phase of oil based bud
Chlorine_Yield	Elemental_Yield	Elemental contribution of Chlorine with respect to total.
Chlorite_Volume_Fraction	Volume_Fraction	The volume fraction of chlorite with respect to the total volume.
Choke_Manifold_Code	Code	Code for the choke manifold
Choke_Manifold_Type	Type	Type of choke manifold
Choke_Size	Inside_Diameter	Internal diameter of the flow choke(s)
Choke_Working_Pressure	Working_Pressure	Working pressure of the choke box which allow for the well fluid flow to be controlled by varying the flow cross-sectional area
Circulating_Line_Pressure	Pressure	Pressure observed at circulating line/BOP
Circulating_Pressure	Pressure	Fluid pressure under circulating conditions.
Circulation_Loss_Depth	Depth	Depth at which circulation is being lost to the formation.
Circulation_Loss_Rate	Flowrate	Rate of loss of drilling fluid to the formation, due to mud density exceeding formation fracture pressure gradient, and/or to drilling through a highly permeable formation.
Classification	Type	Systematic arrangement in groups or categories according to established criteria.
Classification_Group_Code	Type	Associates class definitions into one family: Generic, Unsupervised, Pore_Fluid, Lithologic, Seismostratigraphic, Texture, User_Defined_Mix, User_Defined_No_Mix.
Classification_Index	Explicit_Index	Index into a lookup-table describing various classifications. Typical usage is a surface representation (grid) of index values, where each value represents a particular classification.
Classification_Method_Code	Method_Type	Classification method used in this activity.
Classification_Method_Type	Type	The type of method used for classification: e.g. Statistical, Artificial Neural Net, or Clustering.
Classification_Scope	Type	Per Method expects a maximum of one parameter instance per classification activity. Per Class expects a maximum of as many parameter instances as classes were involved in the classification activity.
Clay_Resistivity	Resistivity	The Resistivity of clay, usually referring to that measured in the Earth formations.
Clay_Volume_Fraction	Volume_Fraction	Volume fraction of clay as calculated, measured or inferred from formation properties.
Client	Organization_Code	The code of a client, usually that of a Service, Contractor, Vendor or E&P company
Client_Representative	Person_Name	Name of the client representative or company man.
Closure	Flag	Indicates whether the boundary of a spatial object is Open or Closed?
Coal_Volume_Fraction	Volume_Fraction	The volume fraction of coal with respect to the total volume.
Cobalt_Concentration	Concentration	Concentration of Cobalt.
Code	Data_Valued_Property	The code, mnemonic, or identifier used to enumerate types, occurrences, or instances of some property or entity.
Code_In_Catalog	Flag	Flag to indicate that the Code is available in a Catalog.
Coefficient	Data_Valued_Property	A number which serves as a measure of some characteristic of a process, substance or device.
Coherence	Data_Valued_Property	A measure of the similarity between two or more functions; used with seismic waveforms to distinguish seismic events and to implement automatic picking schemes.
Coil_Tubing_Section	Ordinal_Number	Number of the Coiled Tubing section used by the CoilLIFE module.
Collapse_Pressure	Pressure	Collapse Pressure.
Color	Data_Valued_Property	The aspect of objects and light sources that may be described in terms of hue, lightness, and saturation for objects and hue, brightness, and saturation for light sources.
Color_Distribution	Color	A descriptive remark with respect to the distribution of a color within the area of a rock surface; e.g. solid, spotty, streaky.
Color_Fluorescent_Light	Color	The color emitted by the fluid upon exposure to fluorescent light. Certain photoactive hydrocarbon molecules display characteristic color patterns under these conditions.
Color_Intensity	Color	A descriptive comment with respect to the intensity of color; e.g. bright, dull, powdery.
Color_Map	Color	Name of entity which maps from Implementation index values to color; GPD_COLOR_MAP arrays are commonly used.
Color_Normal_Light	Color	The color of a hydrocarbon show under normal incident light.
Column_Name	Name	Name of a Column in a database Table.
Companion_Data	Data_Valued_Property	Collection to hold miscellaneous competitor data in any form (parameters, arrays, ...), not described in the Data Model
Company	Organization_Code	The code of a Company, usually that of a Service, Contractor, Vendor or E&P company
Company_Lease_Number	Identifier	Unique lease number assigned by owning company
Company_Type	Type	The type of a Company, e.g. E&P, Service, Contractor, Vendor, etc.
Compartment_Count	Count	Number of independent storage units
Compass_Bearing	Azimuth	The azimuth of an object with respect to magnetic north.
Completed_Thickness	Thickness	Thickness of hydraulic unit actually contributing to the production.
Completion_Count	Count	The count of the number of completions.
Completion_Date	Date	Date that the activities that created the wellbore were completed and the wellbore was available to produce gas or oil, or for other intended service (e.g. gas storage, geothermal, etc.). Common completion activities include running and cementing the "production string" of casing, perforating the casing and cement sheath, installing the production string (tubing, packers, etc.) and the wellhead, etc.
Completion_Skin	Skin_Factor	Skin effect due the completion of the producing interval. It does not include the effect of partially completed interval (plugged perf or bad localization), but it does include Gravel Pack skin.
Completion_Type	Type	Type of well completion.
Compliance	Data_Valued_Property	The relationship of strain to stress, a tensor quantity expressible as the inverse of the stiffness matrix.
Component_1_Name	Name	Name of first component in a mixture or composition.
Component_2_Name	Name	Name of second component in a mixture or composition.
Component_3_Name	Name	Name of third component in a mixture or composition.
Component_4_Name	Name	Name of fourth component in a mixture or composition.
Compressibility	Data_Valued_Property	The change in specific volume and density under pressure; the reciprocal of Bulk Modulus, 1/k.
Compression_Pressure	Pressure	The pressure applied to compress a body or material, as opposed to that applied by tension.
Compressional_Shear_Velocity_Ratio	Ratio	Ratio of velocity of Compressional wave (Vp) to that of Shear wave (Vs).
Compressional_Slowness	Acoustic_Slowness	The time it takes for a compressional wave to traverse a fixed distance; reciprocal of Compressional_Velocity.
Compressional_Velocity	Acoustic_Velocity	Velocity of a compressional acoustic wave (Vp).
Compressional_Velocity_Gradient	Gradient	A measure of the change in the compressional velocity of a medium per unit length.
Compressive_Force	Force	The force tending to compress or squeeze a body.
Compressive_Strength	Strength	The degree of resistance of a material to force acting along one of the axes in a manner tending to crush it.
Computation_Mask	Data_Mask	Application-specific mask for the computation options (one Anadrill example: 0001 - Torque & Drag, 0010 - BHA Tendency, 0100 - Bit Side Forces, 1000 - Buckling, 10000 - Yield Stress)
Computation_Type	Method_Type	Computation method used in the generation of data.
Computed	Modifier	The data related to the property is an output of a process (e.g., Software Module), usually based on input data from a single source.
Concentration	Data_Valued_Property	The relative content of a component; e.g., the concentration of salts in brackish water, the concentration of electric charges in a circuit, etc.
Concentration_1	Concentration	Concentration or proportion of first component in mixture or other composition.
Concentration_2	Concentration	Concentration or proportion of second component in mixture or other composition.
Concentration_3	Concentration	Concentration or proportion of third component in mixture or other composition.
Concentration_4	Concentration	Concentration or proportion of fourth component in mixture or other composition.
Condensate_Flowrate	Flowrate	Rate of flow of condensate
Conductance	Data_Valued_Property	The readiness with which a material conducts electric current; the inverse of resistance. Also, the product of conductivity and thickness.
Conductive_Bed_Proportion	Proportion	Percentage of rock occupied by conductive beds within a given depth interval
Conductive_Inclusion_Contrast	Conductivity_Contrast	Conductivity contrast between conductive inclusions and the surrounding rock
Conductive_Inclusion_Proportion	Inclusion_Proportion	Percentage of rock occupied by conductive inclusions within a given depth interval
Conductive_Inclusion_Size	Surface_Area	Average area of conductive inclusions as seen at the borehole wall
Conductivity	Data_Valued_Property	A measure of the quantity of electricity transferred across unit area per unit potential gradient per unit time. In isotropic material, it is the reciprocal of Resistivity. Sometimes called Specific Conductance.
Conductivity_Contrast	Ratio	Conductivity ratio between geological objects
Confidence_Factor	Indicator	The probability that a given event will occur or that a given data set will contain a specified element.
Confidentiality_Level	Type	Describes the confidentiality of the information related to the well, e.g., Tight (operator only), Sensitive (some restriction), Public
Conicity	Shape	The solid angle measuring the degree of resemblance of a solid to a cone especially in shape.
Conn_1_Approx_Weight	Weight	Approximate weight joint/connection 1
Conn_1_Box_Flag	Flag	Flag indicating if connection is a box (Y) or a pin (N).
Conn_1_Drift_Diameter	Drift_Diameter	Drift diameter of tool joint/connection 1
Conn_1_Inside_Diameter	Inside_Diameter	Inside diameter of tool joint/connection 1
Conn_1_Nom_Length	Length	Nominal length of joint/connection 1
Conn_1_Outside_Diameter	Outside_Diameter	Outside diameter of tool joint/connection 1
Conn_1_Size	Outside_Diameter	Size of the top or the first standard tool connection.
Conn_1_Thread_Type	Thread_Type	Complete and non ambiguous identification of the first threaded connection, e.g., "Hydril Joint Type EIU", "Pittsburgh Special ACME-Thread Casing-Internal-upset"
Conn_1_Type	Type	Type of the top or the first standard tool connection.
Conn_2_Approx_Weight	Weight	Approximate weight joint/connection 2
Conn_2_Box_Flag	Flag	Flag indicating if connection is a box (Y) or a pin (N).
Conn_2_Drift_Diameter	Drift_Diameter	Drift diameter of tool joint/connection 2
Conn_2_Inside_Diameter	Inside_Diameter	Inside diameter of tool joint/connection 2
Conn_2_Nom_Length	Length	Nominal length of joint/connection 2
Conn_2_Outside_Diameter	Outside_Diameter	Outside diameter of tool joint/connection 2
Conn_2_Size	Outside_Diameter	Size of the bottom or second standard tool connection.
Conn_2_Thread_Type	Thread_Type	Complete and non ambiguous identification of the second threaded connection, e.g., "Hydril Joint Type EIU", "Pittsburgh Special ACME-Thread Casing-Internal-upset"
Conn_2_Type	Type	Type of the bottom or second standard tool connection.
Conn_Material	Material_Code	Connection material such as steel, aluminum, plastic
Conn_Tensile_Yield	Tensile_Yield	Maximum force which can be applied to a joint/connection/thread without causing permanent deformation.
Conn_Torsional_Yield	Torsional_Yield	Maximum torque which can be applied to the joint/connection/thread without causing permanent deformation.
Connectedness_Coefficient	Indicator	A coefficient describing the connectedness of items, such as the connectedness between inclusions (e.g. lenses) in the Earth subsurface formations.
Connector_Type	Type	Type of casing or tubing connector according to that particular thread manufacturer; e.g., 8 RD ST&C, 8 RD LT&C, Buttress, Hydril F J-P, Atbrad FL-3S, etc.
Consistency_Index	Coefficient	The k parameter in the Power-Law and Herschel-Bulkley rheological models. The Power_Law model is "Shear_Stress=k times (Shear_Rate at the power of n)". The unit of k is traditionally lbf.sec^n/ft^2 or Pa.s^n.
Constraint_Code	Code	Key Attribute of Object which constrains the Property values. For example, the Domain Attribute in the String_Enum_Cat used to constrain a string-valued Property.
Constraint_Object	Object_Name	Name of Object holding descriptions of the constraints (e.g. String_Enum_Cat)
Constraint_Type	Type	Type of constraint. Examples include UNCONSTRAINED, STRING_ENUM, INTEGER_ENUM, INTEGER_RANGE, FLOAT_RANGE, DATE_RANGE, ENTITY_CLASS, CATALOG_ATTR, etc.
Construct	Type	Construct specifies how instances of the given Value Domain are assembled into a single Value. Together Value Domain and Construct are used to derive Value_Type. Construct can be null (for a single value), L (for List), V (for Vector) , LL (List of Lists) , VL, PL, etc.
Contact_Symbol	Identifier	Symbol to post on the Feature_Boundary at the intersection point with another Feature_Boundary
Contact_Throw_Sense	Type	Specify whether contact corresponds to upthrown or downthrown portion of fault.
Contact_Type	Type	The type of contact or interface between Earth subsurface regions
Container_Code	Code	Code of containing object
Contract_Number	Identifier	Identifying string for contractual agreement
Contract_Status	Status	Status of a contract.
Contractor	Organization_Code	The code of the contractor, usually a company.
Contractor_Representative	Person_Name	Name of the representative of the Contractor Company
Coolant_Temperature	Temperature	Temperature of the cooling fluid
Coord_Sys_Transform_Code	Code	Code for a coordinate system transform method.
Coordinate	Length	Any coordinate of a Location.
Copper_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of copper to total dry weight
Copper_Yield	Elemental_Yield	Elemental contribution of Copper with respect to total.
Copy_Number	Sequence_Number	Number used to identify an instance of a particular type object within a set.
Core_Box_Count	Count	The number of core boxes containing samples from a cored borehole interval in a particular well.
Core_Date	Date	Date on which the core was recovered.
Core_Diameter	Diameter	The Diameter of the recovered core.
Core_Preparation_Method	Preparation_Method	Method by which a core sample has been prepared for analysis.
Core_Preservation_Method	Preservation_Method	Method by which a core sample has been preserved.
Core_Type	Type	Identifies the type of core sample, such as Main, Plug, Slab, Sidewall, etc.
Coring_Fluid_Type	Fluid_Type	The type of fluid that was in the borehole at the time the coring operation was in progress; e.g. water, brine, oil, mud, etc.
Coring_Method	Type	The type of method used to acquire a core sample; e.g. Rotary Conventional, Rotary Sponge, Sidewall Mechanical, etc.
Corrected	Modifier	Generic modifier indicating that data have been corrected and are ready to be analyzed. In practice, many different types of corrections may be applicable.
Corrected_Depth	Depth	Depth which can be offset and scaled from the raw depth acquired from a sensor to take into account the position or deformation of the sensor thus the name of corrected.
Correction	Data_Valued_Property	Correction applicable to a measurement, to remove environmental effects or measurement errors; the unit quantity is determined by that of the data.
Correction_Factor	Coefficient	Coefficient used to correct data, such as for environmental effects.
Correlation_Coefficient	Indicator	Coefficient of a correlation used to determine the quality of the correlation
Correlation_Depth_Dip	Depth_Dip	Dip of seismic data, similar to Depth_Dip but gradient derived from the seismic data (in depth)
Correlation_Time_Dip	Time_Dip	Dip of seismic data, similar to Time_Dip but gradient derived from the seismic data in time)
Corridor_Stack	Acoustic_Amplitude	A summation of the traces in an upgoing Vertical Seismic Profile that have been processed to retain only primary reflection events and that have been time-shifted to their two-way arrival times at the surface. Summation is over a data window (corridor) beginning at the first break time and usually ending 200-300 ms later.
Corrosion_Indicator	Indicator	Any of several measurements which show that material has been damaged by corrosion.
Corrosion_Rate	Velocity	The rate at which corrosion, a complex chemical or electrochemical process by which metal is destroyed, occurs. For example the rate at which a casing pipe rusts (corrodes).
Corrosive_Fluid_Flag	Flag	Is the fluid corrosive? (Y/N) Used to apply a wall erosion model to measure the pipe wall thickness.
Cosine_Of_Phase	Analytic_Trace	Cosine of Instantaneous Phase, also known as normalized seismic amplitude
Cost	Money	Amount of money spent to obtain goods or services.
Cost_Charge_Type	Type	Indicates whether the cost allocation is valid for the start (Start), end (End) of activity or at a given date (User)
Cost_Per_Depth	Cost	Amount of money per unit of length
Cost_Per_Mass	Cost	Amount of money per unit of mass
Cost_Per_Volume	Cost	Amount of money per unit of volume
Coulomb_Friction_Coefficient	Friction_Coefficient	Ratio of contact and friction forces between 2 materials in dry friction conditions i.e. without lubrication (Coulomb law)
Count	Data_Valued_Property	A number indicating the number of occurrences of something.
Count_Rate	Frequency	The number of events per unit time; e.g. the output of a scintillation counters.
Counterion_Conductivity	Data_Valued_Property	The equivalent conductivity of the counterions (cations) in the diffuse layer around clay particles; ratio of conductivity to cation concentration. Refer to Waxman-Smits, Dual-Water models.
Country_Code	Geopolitical_Region_Code	Catalog-controlled code of a Country.
Country_Name	Name	Name of a Country
County_Code	Geopolitical_Region_Code	Catalog-controlled code of a County or Parish.
County_Name	Name	Name of a County or Parish
Covariance	Statistical_Property	A measure of the common variance between two quantities; a non-normalized crosscorrelation function.
Create_Date	Date	Date of creation of a data item in the database.
Critical_Angle	Plane_Angle	Angle of incidence for which a refracted ray follows the surface of contact between two media of different velocities.
Critical_Distance	Seismic_Offset	In seismic work, the offset at which the reflection time equals the refraction time.
Critical_Drawdown_Pressure	Drawdown_Pressure	The upper limit of drawdown pressure that can be applied to a completion system without causing damage to the system (such as erosion to a gravel pack completion system).
Critical_Gas_Saturation	Critical_Saturation	The value of gas saturation at which gas will begin to flow, as gas saturation is increased.
Critical_Oil_Saturation	Critical_Saturation	The value of oil saturation at which oil will begin to flow, as oil saturation is increased.
Critical_Pressure	Pressure	The pressure needed to condense a vapor at its critical temperature. Applies to pure components; for mixtures use Pseudocritical_Pressure.
Critical_Saturation	Saturation	The value of saturation of a specific fluid phase at which the fluid will first begin to flow as saturation is increased.
Critical_Temperature	Temperature	The highest temperature at which a fluid can exist as a liquid and above which its vapor cannot be liquefied regardless of the amount of pressure. Applies to pure components; for mixtures use Pseudocritical_Temperature.
Critical_Volume	Data_Valued_Property	The inverse of density at the critical point of a fluid, describing the volume occupied by a fluid of unit mass.
Critical_Water_Saturation	Critical_Saturation	The highest water saturation a hydrocarbon-producing rock can maintain before water will begin to flow.
Cross_Section_Area	Surface_Area	The cross-sectional area of a solid object; e.g., area of perforation in a cased borehole.
Crossflow_Coefficient	Coefficient	Characterization of the flow in the reservoir from one layer to another layer, usually known as "Omega" in Reservoir Dynamics
Crossflow_Flag	Flag	Indicates presence of crossflow
Crossline_Dip	Dip_Angle	Angle that a surface, e.g. a bedding or fault surface, makes with the horizontal, measured in the cross-line direction.
Crossplot_Porosity	Apparent_Porosity	Estimate of porosity determined by plotting one type of data against another.
Crushed_Zone_Permeability	Permeability	Permeability of the Crushed Zone around perforation
Crushed_Zone_Thickness	Thickness	Thickness of the Crushed Zone around perforation
Cultural_Feature_Type	Type	The type of cultural feature that is to be found on a map
Cumulative_Borehole_Volume	Borehole_Volume	Cumulative volume of the borehole (integrated over length of borehole).
Cumulative_Cement_Volume	Cement_Volume	Cumulative volume of cement (may be integrated over length of borehole or over time of cementing operation).
Cumulative_Condensate_Volume	Cumulative_Production_Volume	Cumulative condensate production.
Cumulative_Equivalent_Time	Time_Interval	Cumulative Equivalent Operating Time, called Cumulative Time Usage or CTU.
Cumulative_Gas_Volume	Cumulative_Production_Volume	Cumulative gas production at standard conditions. At constant BHP or WHP, cumulative volume is not the straightforward sum of volume by RHU but determined by Inverse Laplace transformation.
Cumulative_Oil_Volume	Cumulative_Production_Volume	Cumulative oil production at standard conditions. At constant BHP or WHP, cumulative volume is not the straightforward sum of volume by RHU but determined by Inverse Laplace transformation.
Cumulative_Production_Volume	Volume	Volume of fluids produced by a zone or interval since the beginning of the production
Cumulative_Volume	Volume	The cumulative volume, typically of a fluid.
Cumulative_Water_Influx	Volume	The cumulative volume of water that encroaches into a reservoir.
Cumulative_Water_Volume	Cumulative_Production_Volume	Cumulative water production at standard conditions.
Currency_Code	Code	Money currency (US$, French franc..)
Current_Density	Data_Valued_Property	Current per unit cross-sectional area.
Current_Equivalent_Time	Time_Interval	Computed equivalent operating time based on the time spent at a given temperature and the maximum working temperature. If all the time is spent at maximum working temperature, then the equivalent time is equal to the operating time.
Curvature	Shape	A measure of the degree to which a path is curved relative to the length of the path along the curve.
Curvature_Radius	Radius	Radius of the circle whose arc would have a given curvature.
Cushion_Type	Type	Type of fluid in the test string prior to initial open of the well.
Cutter_Count	Count	Number of cutters, as for drilling hole openers and reamers.
Cutter_Set_Weight	Weight	Approximate weight of the set of cutters
Cutter_Type	Type	Type of cutters, as used in drilling reamers (such as Type T, F, or B)
Cuttings_Diameter	Diameter	Average diameter of drill cuttings.
Cycle_Sample_Count	Count	Target number of samples per hour.
Cyclic_Redundancy_Check	Quality_Indicator	CRC test value for this Calibration Coefficient set.
Cylindrical_Position	Location	Set of coordinates specifying the position of a point in a cylindrical coordinate system
DST_Gauge_Adapter_Code	Code	Code for the DST Gauge Adapter
DST_Gauge_Type	Type	Type of DST Gauge Adapter
Daily_Prognosis	Description	Description of activities and events anticipated during the next 24 hours.
Damaged_Zone_Mobility	Mobility	Mobility of the near-wellbore Damaged Zone, the sandface layer around the wellbore where permeability and mobility are impaired, generally by a damaging material (e.g. completion or drill mud).
Damaged_Zone_Permeability	Permeability	Permeability of the near-wellbore Damaged Zone, the sandface layer around the wellbore where permeability and mobility are impaired, generally by a damaging material (e.g. completion or drill mud).
Damaged_Zone_Thickness	Thickness	Thickness of the near-wellbore Damaged Zone, the sandface layer around the wellbore where permeability and mobility are impaired, generally by a damaging material (e.g. completion or drill mud).
Data_Acquisition_Mode	Indicator	Software or hardware option whose selection controls some aspect of data acquisition.
Data_Compression_Flag	Flag	Flag indicating whether or not downhole data compression is possible with this equipment.
Data_Direction	Type	Direction of data flow, e.g. Input, Output or both.
Data_Focus_Type	Type	Indicates how the entity set to be used as the starting point of a query is formed.
Data_Mask	Data_Valued_Property	Data pattern which allows storage and access of several types of independent data within a simple representation; common masks use individual bits of integer representations, or individual characters of string representations, to carry independent information.
Data_Presence_Flag	Flag	An indicator which shows that some particular type of data is available.
Data_Reduction_Type	Type	Method used for data reduction, e.g. Linear decimation, Logarithmic, etc.
Data_Valued_Property	Property	A property whose value contains data.
Date	Absolute_Time	The date, usually expressed in the format of the DBMS; e.g., Oracle date format is dd-mm-yy.
Date_Format	Format	Specification of how date information will be formatted.
Dead_Volume	Volume	Volume of material remaining in a container after normal emptying procedure, and thus not available for use.
Dead_Weight	Mass	Weight of material unavailable for use remaining in a container
Decimation_Factor	Coefficient	Number indicating the degree of data reduction from decimation (resampling at lower sampling frequency); e.g. a Decimation_Factor of 5 indicates that only every 5th input sample is retained as output.
Declination	Plane_Angle	The angle between the celestial equator and a celestial body, measured along a great circle passing through the celestial poles.
Deep_Conductivity	Conductivity	The conductivity which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.
Deep_Induction_Conductivity	Deep_Conductivity	The conductivity, measured by an induction log, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.
Deep_Induction_Resistivity	Deep_Resistivity	The resistivity, measured by an induction log, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.
Deep_Lateral_Resistivity	Deep_Resistivity	Resistivity measurement using a "lateral" electrode arrangement with a "deep" investigation radius (several feet into the formation).
Deep_Laterolog_Conductivity	Deep_Conductivity	The conductivity, measured by a laterolog (or guard log) resistivity device, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.
Deep_Laterolog_Resistivity	Deep_Resistivity	The resistivity, measured by a laterolog (or guard log) resistivity device, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.
Deep_Resistivity	Resistivity	The resistivity which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.
Def_Currency	Name	Default Currency used
Def_Display_Type	Type	Default type of display used for a data object, such as an Array.
Def_Language	Language	Default Language used
Def_Unit	Unit_Code	Code of default Unit
Def_Unit_System	Unit_System_Code	Default Unit System used
Def_Value_Number	Multi_Use_Property	Default value if number
Def_Value_String	Multi_Use_Property	Default value if string
Definition	Description	A full textual description of the meaning of a term.
Degradation_Factor	Quality_Indicator	Indication of the extent to which the quality of an object or of data has been degraded.
Degree_Of_Confidence	Quality_Indicator	The degree of confidence associated with any event or feature related to or detected, for example a geologic feature in/on the Earth (high, low, etc)
Delay_Time	Time_Interval	The time difference by which one event lags another. In refraction seismic work, the additional time required to traverse a raypath over the time which would be required to traverse the horizontal component at the highest velocity encountered on the raypath.
Density	Data_Valued_Property	The density (mass per unit volume) of a material. Usually at Standard conditions (STP). Also used to indicate the frequency of occurrence.
Density_Caliper	Caliper	Borehole diameter as estimated by a density logging device.
Density_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a bulk density logging measurement.
Density_Gradient	Gradient	A measure of the change in the density of a material per unit length.
Density_In	Density	Density of the input material, such as the drilling fluid in the mixing tank.
Density_Out	Density	Density of the output fluid, such as the drilling fluid returning from the well annulus.
Density_Porosity	Apparent_Porosity	Porosity derived from a formation density measurement.
Density_Porosity_Dolomite	Density_Porosity	Porosity derived from a formation density measurement, assuming that the rock matrix material is dolomite.
Density_Porosity_Limestone	Density_Porosity	Porosity derived from a formation density measurement, assuming that the rock matrix material is calcite.
Density_Porosity_Sandstone	Density_Porosity	Porosity derived from a formation density measurement, assuming that the rock matrix material is quartz.
Density_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from a density logging survey.
Density_Time_After_Bit	Time_After_Bit	In MWD/LWD logging, the time delay between the drill bit and a density sensor reaching a given point in the wellbore.
Depositional_Environment_Type	Type	The type of deposition that has created a particular Earth environment, e.g. Reef, Beachrock, Pointbar, etc.
Depth	Length	The perpendicular measurement downward from a surface. Also, the direct linear measurement from the point of viewing usually from front to back.
Depth_Dip	Dip_Angle	Dip computed on a depth surface by measuring the difference in depths between two points compared to the horizontal distance between the points.
Depth_Increment	Interval_Length	Length of interval which is used as a regular increment to depth-based processing.
Depth_Offset	Length	Offset in depth versus some depth reference.
Depth_Unit	Unit_Code	Unit for depth data
Depth_Value_Type	Value_Type_Code	Value type of depth data
Derivative_Model	Type	Derivative Model used in evaluating this Transient, e.g., Backward, Central, or Forward.
Derivative_Type	Type	Type of derivative used in evaluating this transient.
Derived	Modifier	The data related to the property is an output of empirical equations or other equations based on input data from multiple sources.
Derived_Inverse_Flattening	Flag	Flag indicating that the inverse flattening value of an ellipsoid has been derived from semi-major and semi-minor axis lengths.
Derived_Minor_Axis	Flag	Flag indicating that the semi-minor axis value of an ellipsoid has been derived from the semi-major axis length and a flattening value.
Description	Data_Valued_Property	The description or complete definition of any data item or object
Detection_Gain	Coefficient	Coefficient used to adjust signal amplitude for detection of some event, such as the first arrival in a sonic waveform.
Deviation	Plane_Angle	Angular departure from some reference direction. When used with wells, it is the angle between the borehole axis and the vertical (also known as the Drift Angle).
Deviation_Skin	Skin_Factor	The skin effect caused by the well trajectory not being perpendicular to the bedding plane.
Dew_Point_Pressure	Pressure	The pressure at which a liquid phase condenses from a vaporous fluid in equilibrium at a given temperature.
Diameter	Length	Length from one side of an object to the other measured along a straight line through the center of the object
Diameter_Restriction	Description	Description of the change in diameter within a well or a borehole.
Diameter_Unit	Unit_Code	Unit for diameter data.
Dielectric_Constant	Permittivity	The ratio of the Permittivity of a material to that of free space.
Dielectric_Resistivity	Resistivity	Resistivity measurement which has been compensated for the dielectric constant of the formation..
Diff_Pressure_Gauge_Type	Type	Sensor used to acquire gas differential pressure across orifice plate
Differential_Caliper	Diameter	The difference between the actual borehole diameter and bit size.
Differential_Pressure	Pressure	The difference between the pressures of two systems, or between the pressures measured at different points in a system.
Differential_Speed	Angular_Velocity	The differential speed between the bowl and the conveyor of a centrifuge.
Differential_Temperature	Temperature	The difference in temperature between two objects or materials.
Diffusivity	Data_Valued_Property	A measure of the tendency for diffusion to occur. See Hydraulic_Diffusivity.
Digital_Encoding	Format	Identification of how data are encoded digitally; e.g. ASCII, Binary, etc.
Digital_File_Format	Format	The type of file structure in which the depiction rendering is encoded; e.g. PostScript, ANSI text, GIFF, JPG, Maker Interchange Format (MIF), SGML, HTML.
Digital_File_Format_Version	Version	Identification of the digital file format version (e.g., 3.0a). Note that this information is often encoded within the file.
Dilation_Angle	Plane_Angle	Angle relating the increase in volumetric strain with stress.
Dimension_Count	Count	The number of dimensions for an object or a representation of such an object, e.g. dimensions of an array.
Dimensionless_Borehole_Radius	Borehole_Radius	Dimensionless Borehole Radius ("rwD")
Dimensionless_Boundary_Distance	Well_To_Boundary_Distance	Distance to a boundary divided by wellbore radius
Dimensionless_Changing_Storage_Pressure	Pressure	Dimensionless changing wellbore storage pressure ("CphiD")
Dimensionless_Fracture_Conductivity	Fracture_Conductivity	Ratio of fracture conductivity (fracture permeability x average width) to the (matrix permeability x fracture half_length) product. Standard industry acronym : "FCD", S.P.E. preferred form "CfD".
Dimensionless_Interwell_Distance	Interwell_Distance	Dimensionless inter-well distance for a horizontal interference test
Dimensionless_Layer_Diffusivity	Layer_Diffusivity	Ratio of layer storativity ratio to layer transmissibility ratio ("etaDj")
Dimensionless_Rectangle_Length	Rectangle_Length	Rectangle length divided by reference length ("BxD")
Dimensionless_Rectangle_Width	Rectangle_Width	Rectangle width divided by reference length ("ByD")
Dimensionless_Well_X_Position	X_Coordinate	Well position expressed as fraction of rectangle length ("xbx")
Dimensionless_Well_Y_Position	Y_Coordinate	Well position expressed as fraction of rectangle width ("yby")
Dip_Angle	Plane_Angle	The maximum vertical angle that a surface; e.g. a bedding or fault surface, makes with the horizontal, measured perpendicular to the strike direction of the structure. Dip may be computed in several ways, including from logs, from well-to-well correlation, from gradients on interpreted time or depth surfaces (See Time_Dip and Depth_Dip), etc.
Dip_Azimuth	Azimuth	Azimuth of the direction of maximum dip of a surface; dip may be computed in several ways, including from logs, from well-to-well correlation, from gradients on interpreted time or depth surfaces, etc.
Dip_Detection_Source	Source	The source of information used to detect dips (e.g., Seismic data, Structural analysis, Dipmeter log data, etc.)
Dip_Height	Height	Height of Dip Plane Intersection with Borehole
Dip_Number	Ordinal_Number	An ordinal identifier that characterizes uniquely each dip
Dip_Pattern_Shape	Shape	Shape of a dip pattern, e.g. Convex, Concave, etc.
Dip_Pattern_Type	Type	The type of pattern created by the earth dipping planes, e.g. Green, Red, Blue, etc.
Dip_Quality	Quality_Indicator	Induced quality of the dip value based on evaluation of the quality of the measured data. Ranges from 0 (bad) to 20 (good)
Dip_Quality_Cutoff	Quality_Indicator	The lowest dip quality taken into account for an interpretation.
Dip_Type	Type	The type of dipping associated with subsurface planes; e.g., CrossBedding, Fault, Fracture, BedBoundary, etc.
Dip_Valid_Zone_Type	Type	This property specifies whether the zone where the dips were computed corresponded to a Blank zone with no dips, a Mirror Image zone, or a borehole Washout zone.
Direction	Orientation	The line or course on which something is moving or is aimed to move or along which something is pointing or facing.
Direction_Channel_To_Axis	Azimuth	Azimuth of the direction to an axis, usually pertaining to a sedimentary channel.
Direction_Channel_To_Flow	Azimuth	Azimuth of the direction to flow, usually pertaining to a sedimentary channel.
Direction_Channel_To_Land	Azimuth	Azimuth of the direction to land, usually pertaining to a sedimentary channel.
Direction_Current	Azimuth	The azimuth of the flow direction that insured transportation an deposition of the sediments.
Direction_Downthrown_Block	Azimuth	Azimuth of the direction to the downthrown block in case of faulting in the Earth subsurface.
Direction_Overthrust	Azimuth	Azimuth of the direction of overthrust in case of faulting in the Earth subsurface.
Direction_To_Source	Azimuth	The direction from which sediments are brought
Directional_Permeability	Permeability	An oriented permeability within a porous media, expressed either as horizontal (along the bedding plane of the stratum) or vertical (perpendicular to the bedding plane of the stratum), or within a coordinate system.
Disclaimer	Data_Valued_Property	Legal text on the front page describing the legal status of this document as regard of liability.
Discontinuity_Type	Type	The type of discontinuity: a detectable interruption in the material which may or may not have undesirable connotations (e.g. crack, lap, seam, pit, lamination, etc.)
Discriminator_1_Cutoff	Threshold	Cutoff value for first discriminator
Discriminator_2_Cutoff	Threshold	Cutoff value for second discriminator
Displaced_Fluid_Type	Fluid_Type	Type of fluid displaced by the injection of another fluid.
Displacement	Length	The linear distance which a point or object is displaced with respect to another, usually as the result of some activity or process.
Displacement_Efficiency	Efficiency	The fraction of displaceable fluids/hydrocarbons that has been actually displaced when contacted by a displacing fluid.
Displacement_Velocity	Velocity	The velocity of the shock or displacement front.
Displacing_Fluid_Volume	Volume	Volume of fluid used to displace another fluid. In special core analysis, may be expressed as unitless multiple of pore volume.
Display_Index_Type	Axis_Index_Code	Type of index used for display; e.g. MD, DSRD, TVD etc.
Display_Name	Name	A name which is used for display purposes, as opposed to the formal controlled name (Code) which is used for interoperability.
Display_Name_Format	Format	Specification of how the name of a data item will be displayed to the user.
Distance	Length	Amount of separation between two points, lines, surfaces, or objects measured along the shortest path joining them.
Distance_Unit	Unit_Code	Unit for distance data, typically m or ft.
Documentation_File	File_Name	Name of file containing related documentation
Dolomite_Volume_Fraction	Volume_Fraction	The volume fraction of dolomite with respect to the total volume.
Dominant_Frequency	Frequency	Predominant frequency within power spectrum.
Dominant_Wavenumber	Wavenumber	Dominant Wavenumber in depth domain. Reciprocal of distance between successive peaks or troughs.
Dosing_Mode	Type	The way an additive is measured e.g. By Weight Of Cement, BOW, gl/sk ....
Dowell_Chemical_Code	Code	Reference to the Dowell chemical product catalog
Down_Load	Load	Downward load exerted on an equipment item.
Down_Stroke	Stroke_Length	Down stroke distance, as used for drilling jars.
Downhole_Cable_Tension	Tension	Tension of the logging cable as measured at the top of the logging tool
Downhole_Inclination	Hole_Deviation	Inclination of the drillstring as measured downhole
Downhole_Torque	Torque	Downhole torque, as applied to the drill string
Downstream_Coil_Pressure	Pressure	Coil working pressure downstream of the choke box
Downstream_Orifice_Gas_Pressure	Pressure	Pressure of gas separator gas line downstream of orifice plate when a sample is taken
Downtime	Time_Interval	Time during which equipment is not operational condition or is otherwise unavailable.
Downtime_Ratio	Ratio	Non-operational time of an equipment with respect to total time in location
Drag	Force	In drilling, the extra force needed to move the drillstem resulting from the drillstem being in contact with the borehole wall.
Drainage_Area	Surface_Area	The drainage area of a reservoir.
Drainage_Area_Shape_Factor	Indicator	The shape factor for enclosed drainage areas, used to correct pseudosteady-state flow performance behavior of sinks in non-circular drainage regions.
Drawdown_Pressure	Bottomhole_Pressure	The difference in shut in and flowing bottomhole pressures, at a constant rate of fluid production.
Drift_Diameter	Inside_Diameter	Largest diameter of a perfect cylinder of a specified length that can fit into the pipe. Because a pipe is never perfectly cylindrical but slightly oval the drift diameter is always smaller than the quoted inner diameter. The drift diameter is used to know if a given pipe or instrument will run into a pipe.
Drift_Gradient	Gradient	The change in the borehole drift per length, usually referring to the borehole measured depth.
Drift_Time	Time_Interval	The difference between actual acoustic travel time to a subsurface point (as measured in a check shot survey) and the integrated acoustic slowness from sonic logging data.
Drill_Bit_Code	Code	Specific drill bit code given by the manufacturer and usually approved by the IADC.
Drill_Bit_Grade_IADC	Grade	The IADC, the International Association of Drilling Contractors, grading of a drill bit based on certain criteria; e.g., Bearing Seals, Dull Characteristic, Gauge, etc. grading.
Drill_Bit_Grade_TBG	Grade	The TBG, Teeth-Bearing-Gauge, grading assigned to a drill bit based on particular criteria. The TBG has 5 fields: Bearing, Broken Teeth, Gauge, Gauge Out of Hole, Tooth Wear.
Drill_Bit_Grade_Wear	Grade	Drill Bit wear grading in percentage.
Drill_Bit_Type	Type	Generic type of the drill bit, such as Roller Cone or PDC.
Drill_Collar_Type	Type	Generic type of drill collar, such as spiral, normal, slip & elevator
Drill_Downhole_Tool_Code	Code	Specific code of the downhole drilling tool.
Drill_Downhole_Tool_Type	Type	Generic type of downhole drilling tool.
Drill_Fluid_Code	Code	Specific code of the drill fluid.
Drill_Fluid_Name	Name	Name given to the drill fluid
Drill_Fluid_Type	Fluid_Type	Generic type of the fluid used during a drilling activity; e.g., chemical gel mud, crude oil, caustic (high ph), gypsum mud, native mud, air, salt water, etc.
Drill_Fluid_Volume	Volume	Volume of drilling fluid
Drill_Hole_Opener_Reamer_Code	Code	Specific code of the hole opener or reamer.
Drill_Hole_Opener_Reamer_Type	Type	Generic type of tool i.e. standard, bull nose hole opener, underreamer, LHO (Large Hole Opener with rollers),roller reamer, 3-Point Roller Reamer, 6-Point Roller Reamer
Drill_Jar_Shock_Code	Code	Specific code of the drill jar or shock sub.
Drill_Jar_Shock_Type	Type	Generic type such as hydraulic jar, mechanical jar, shock sub
Drill_Motor_Code	Code	Specific code of the Motor or Turbine.
Drill_Motor_Type	Type	Generic type of the Motor or Turbine used during a drilling activity.
Drill_Operation_Mask	Data_Mask	Mask for the drilling operating mode, such as 0001 - Rotating, 0010 - Sliding, 0100 - Reaming, 1000 - Trip in, 10000 - Trip out
Drill_Pipe_Grade	Grade	Drill pipe grade
Drill_Pipe_Type	Type	Generic drill pipe type such as Normal Grade, Heavy Weight, Hevi-Wate, or Thick Wall
Drill_Slot_Cluster_Type	Type	Generic type of drill slot cluster such as template and pad
Drill_Stabilizer_Code	Code	Specific code of the drill stabilizer.
Drill_Stabilizer_Type	Type	Generic stabilizer type such as Welded Blade, Integral Blade, Replaceable Sleeve, Clamp-on, Rubber Sleeve, Rockback, RWP (replaceable wear pad)
Drill_Structure_Code	Code	Code which uniquely identifies a particular drill structure
Drill_Structure_Name	Name	Name of the Rig or Drill Structure operating on the well
Drill_Structure_Type	Type	Generic type of drilling structure such as land rig, barge rig, submersible rig, jack-up rig, semisubmersible rig, drillships, structure rig
Drill_Sub_Type	Type	Type of sub - bent, bent orienting, cross-over, bitsaver, kelly-saver, extension, UBHO (Universal Bottom Hole Orienting), float, saver, lift, pressure release, etc
Drill_Survey_Tool_Code	Code	Specific code of survey tool.
Drill_Survey_Tool_Type	Tool_Type	Generic type of survey tool such as single shot, multi shot, gyro.
Driller_Elevation_Reference_Code	Code	Code of the elevation reference for drilling data
Driller_Total_Depth	Total_Depth	The total depth of the well borehole as reported by the drilling contractor.
Drilling_Time	Operating_Time	Elapsed time during which drilling has taken place.
Drillstring_Drive_Torque	Torque	Torque applied to the drillstring, measured at the rotary table or top-drive.
Dry_Clay_Volume_Fraction	Volume_Fraction	The volume fraction of dry clay with respect to the total volume.
Dry_Gas_Critical_Pressure	Critical_Pressure	The pressure needed to condense a dry gas at its critical temperature (Dry gas = free gas without condensate)
Dry_Gas_Critical_Temperature	Critical_Temperature	The highest temperature at which a gas can exist as a liquid and above which its vapor cannot be liquefied regardless of the amount of pressure (Dry gas = free gas without condensate)
Dry_Gas_Gravity	Gas_Gravity	The ratio of the molecular weight of the dry gas to that of air (Dry gas = free gas without condensate)
Dry_Weight_Fraction	Ratio	The ratio of the dry weight of a component of a system to the total dry weight of the system.
Dune_Shape	Shape	Shape of a Dune type depositional environment, e.g. Dome, Parabolic, etc.
Duration	Time_Interval	Elapsed time from the start to the finish of a process or activity.
Duration_Unit	Unit_Code	Unit for this Data
Duty_Cycle	Data_Valued_Property	Amount of time it takes to start, operate, stop and idle a machine when it is used for intermittent duty; also, proportion of working time as compared to total operating time.
EOU_Computation_Method	Method_Type	Method used for calculating the ellipse of uncertainty: 0 - Wolfe & de Wardt; 1 - Conic
EOU_Cone_Depth_Increment	Depth_Increment	Depth increment of the ellipse of uncertainty cone
EOU_Cone_Growth_Ratio	Ratio	Ratio of the ellipse of uncertainty cone radius increase per depth increment
EOU_Cone_Surface_Radius	Radius	The radius of the ellipse of uncertainty cone at the surface location
East_Departure	X_Coordinate	Displacement to the East relative to some coordinate system origin; e.g., the east component of the well departure from the vertical. (Negative value is departure to the West.)
East_West_Distance	X_Coordinate	East or West distance from the boundary line indicated by East_West_Line to the survey point.
East_West_Line	Type	Indicates whether the East or West boundary line of the survey area has been used as a reference for East_West_Distance values.
Eastern_Meridian	Longitude	The meridian on a graticule that is the eastern extreme on a map projection.
Eccentering	Length	A measure of the amount by which an object is off-center with respect to another; e.g. the displacement between the axis of a logging tool and the borehole axis.
Eccentering_Azimuth	Azimuth	Azimuth of the line from the center of an area to an eccentered object.
Eccentering_Azimuth_Offset	Plane_Angle	Offset in azimuth due to eccentering; used to convert azimuth values with respect to an eccentered position into azimuth values relative to center.
Eccentricity	Shape	The ratio of the focus-to-center distance to the length of the semi-major axis of an ellipse.
Eccentricity_Squared	Shape	The square of the ratio of the focus-to-center distance to the length of the semi-major axis of an ellipse.
Echo_Amplitude	Amplitude	The amplitude of an echo signal.
Eff_Formation_Stress	Stress	Effective Stress of completed interval
Eff_Inside_Diameter	Inside_Diameter	Effective inside diameter for stiffness, as used for drilling tools.
Eff_Reservoir_Radius	Reservoir_Distance	The characteristic radius of a reservoir used to quantify the behavior of a reservoir. This is the radius that a reservoir would have if circular in shape.
Effective_Date	Date	The date on which a contract becomes effective or put in force.
Effective_Length_Thickness_Ratio	Ratio	A measure of the tendency of a permeable stratum to exhibit vertical equilibrium of flowing fluids, defined as: (length / height) * SQRT(kv/kh), where length is the characteristic length of the flow path and height is the gross or net height.
Effective_Permeability	Permeability	The measure of the capacity of a single fluid to flow through a rock when the pore spaces of the rock are not completely filled or saturated with the fluid.
Effective_Permeability_Gas	Effective_Permeability	The measure of the capacity of gas to flow through a rock when the pore spaces of the rock contain other fluids.
Effective_Permeability_Gas_Sor	Effective_Permeability_Gas	Effective permeability to gas at residual oil saturation.
Effective_Permeability_Gas_Swi	Effective_Permeability_Gas	Effective permeability to gas at initial water saturation.
Effective_Permeability_Gas_Swr	Effective_Permeability_Gas	Effective permeability to gas at residual water saturation.
Effective_Permeability_Oil	Effective_Permeability	The measure of the capacity of oil to flow through a rock when the pore spaces of the rock contain other fluids.
Effective_Permeability_Oil_Swi	Effective_Permeability_Oil	Effective permeability to oil at initial water saturation.
Effective_Permeability_Water	Effective_Permeability	The measure of the capacity of water to flow through a rock when the pore spaces of the rock contain other fluids.
Effective_Permeability_Water_Sor	Effective_Permeability_Water	Effective permeability to water at residual oil saturation.
Effective_Porosity	Porosity	The porosity available to free fluids, excluding non-connected porosity and space occupied by bound water.
Efficiency	Data_Valued_Property	The ratio of the useful energy delivered by a dynamic system to the energy supplied to it.
Elastic_Impedance	Acoustic_Impedance	Property which controls the propagation of a seismic wave at a particular (non-zero) angle of incidence. It is a function of the material density, the compressional wave velocity within the material, the ratio between the shear and the compressional wave velocities, and the angle of incidence. This property, analogous to Acoustic_Impedance but for non-zero incidence angles, is described in 1998 SEG Paper "Calibration and Inversion of Non-Zero Offset Seismic Data", by Patrick Connolly (BP).
Elastic_Limit	Pressure	The greatest stress that can be applied to a body without causing permanent deformation.
Elastic_Modulus	Pressure	The stress-strain properties of isotropic materials which obeys Hooke's law, for small formations, are specified by elastic moduli.
Electric_Charge	Data_Valued_Property	A definite quantity of electricity.
Electric_Current	Data_Valued_Property	Flow of electric charge within an electromagnetic field, per unit time.
Electric_Field_Strength	Gradient	The force per unit charge (or voltage gradient).
Electric_Potential	Data_Valued_Property	A measure of Voltage
Electric_Potential_Gradient	Gradient	Electric potential difference per unit of length.
Electric_Susceptibility	Data_Valued_Property	Ratio of electric field strength to electric polarization.
Electrical_Penetration	Borehole_Diameter	The apparent borehole diameter as viewed by electrical measurements
Electrical_Property	Data_Valued_Property	Coarse classification of the electrical nature of a material; e.g. Conductive, Resistive
Electrical_Stability	Data_Valued_Property	Measure of the emulsion stability and oil-wetting capability in oil based drilling fluids.
Electrochemical_Equivalent	Data_Valued_Property	The mass in grams of a substance produced or consumed by electrolysis (with 100% current efficiency) during the flow of a quantity of electricity equal to 1 Faraday (96,487 Coulombs); conventional unit is the "equivalent" (eq).
Electrochemical_Potential	Electric_Potential	The component of the Spontaneous or Self Potential comprised of the sum of the liquid-junction and the shale-membrane potentials, both of which are related to ratio of the activity of the formation water to that of the mud filtrate.
Electrokinetic_Potential	Electric_Potential	A voltage which results from the flow of a fluid containing ions. A component of the Spontaneous or Self Potential.
Electromagnetic_Attenuation_Rate	Attenuation_Rate	A measure of the rate of attenuation of an electromagnetic wave per unit length.
Electromagnetic_Caliper	Caliper	Borehole diameter as estimated by an electromagnetic logging device.
Electromagnetic_Phase_Shift	Phase_Shift	Difference in phase of two electromagnetic waves.
Electromagnetic_Power	Power	The rate at which electromagnetic energy is emitted or transferred.
Electromagnetic_Propagation_Resistivity	Resistivity	Formation resistivity as measured by the attenuation or phase shift of a high frequency electromagnetic wave; the frequency range for these measurements is higher than that of induction measurements, typically hundreds of KHz to several MHz, and over 1 GHz in the case of the Schlumberger EPT tool.
Electromagnetic_Propagation_Time	Interval_Transit_Time	Time per unit length required for an electromagnetic wave to propagate over some interval in some medium like air, water, drilling fluid, etc..
Electron_Density	Bulk_Density	Electron density. Gamma-gamma logging techniques respond to electron density, which is near bulk density for most formation types.
Element_Code	Code	Code of the Element type that participates in this collection. If NULL, any type is allowed in the collection.
Element_Count	Count	The number of elements, usually in an array or along an axis.
Element_Table	Table_Name	Table containing an element of a collection.
Element_Tag	Name	Tag (label) used to reference an Element of a Collection.
Elemental_Yield	Data_Valued_Property	The fractional contribution of an element to the total; in induced gamma-ray spectroscopy, it is the fraction of the counts in the measured spectrum due to a given element.
Elevation	Height	Height of some point above a horizontal reference plane.
Elevation_CDP	Elevation	Surface elevation at a CDP with respect to mean sea level.
Elevation_Reference_Code	Code	Code of the local elevation reference, such as "KB" for "Kelly Bushing".
Elevation_Reference_Name	Name	Name of the local elevation reference, such as "Kelly Bushing".
Ellipsoid_Code	Code	Code of the ellipsoid to which geodetic coordinates are referenced.
Ellipsoid_Name	Name	Name of the ellipsoid to which geodetic coordinates are referenced.
Ellipticity	Shape	The ratio of the major to minor axes of an ellipse.
Email_Address	Address	Address used for electronic mail, such as an Internet address (clinton@white_house.gov)
End_Age	Geologic_Age	The latest (numerically smallest) geologic or geochronologic age associated with an event or item, such as an earth layer, a fossil or pollen type.
End_Age_Code	Geologic_Age_Code	The code of the latest (most recent) geologic or geochronologic age associated with an event or item, such as an earth layer, a fossil or pollen type.
End_Date	Date	The date/time of the end of an activity.
End_Time	Absolute_Time	Time at which a process ended
Energy	Data_Valued_Property	Capacity for doing work
Energy_Half_Depth	Energy_Half_Z	Depth, within a specified interval, at which half the energy of the interval occurs
Energy_Half_Time	Energy_Half_Z	Time, within a specified interval, at which half the energy of the interval occurs
Energy_Half_Z	Ratio	Characterization of relative distribution of energy in a layer, computed as the fractional displacement (depth or time) into an interval (layer, bed) where half of the energy is above, half below.
Engine_Oil_Pressure	Pressure	Pressure of the lubrication oil
Engine_Oil_Temperature	Temperature	Engine lubrication Oil Temperature
Engine_Total_Time	Operating_Time	Time spent by an engine in operating condition since the last overhaul.
Enhanced	Modifier	Made greater (as in value).
Enthalpy	Energy	The internal energy of a thermodynamic system plus the product of its pressure and volume.
Entity_Code	Code	Code of SDM Entity
Entity_Object	Object_Name	Name of the implementation object of the entity. A table name in a relational implementation.
Epithermal_Neutron_Near_Far_Ratio	Ratio	Ratio of the count rate of the near detector to that of the far detector in an epithermal neutron logging device
Epithermal_Neutron_Porosity	Neutron_Porosity	Porosity as measured with an epithermal neutron device.
Equilibration_Ratio	Ratio	The equilibrium vaporization ratio, or ratio of the mole fraction of a fluid system component in the vapor phase divided by the mole fraction of the same component in the liquid phase.
Equipment_Test_Pressure	Pressure	Recommended pressure the equipment is tested when inspected or certified
Equipment_Type	Type	The type or class of an equipment used for some activity, e.g. Sensor, Drill Bit, Turbine, etc.
Erosion_State	Status	Describes if the event has been partially, totally, etc. subjected to erosion.
Error	Statistical_Property	The deviation of a measurement from the true value; usually expressed as an absolute quantity rather than as a fraction; the unit quantity is determined by that of the data.
Error_Band	Statistical_Property	Tolerance range within which the measurement should remain; the sum of the positive and negative tolerances. May be scaled in measurement units or expressed as a proportion of the instrument rating.
Estimated	Modifier	Obtained using a rough or approximate calculation, such as a numerical value obtained from a statistical sample and assigned to a population parameter.
Estimated_Borehole_Volume	Borehole_Volume	The estimated volume of the Open Hole used in fluid volume/placement computations
Estimation_Flag	Flag	Indicates whether the data are an estimation (Y) or not (N)
Etched_Half_Length	Length	Half Length of formation etched (dissolved) by reaction with acid (Acid fracturing)
Etched_Width	Width	Width of formation etched (dissolved) by reaction with acid on the fracture face (Acid fracturing)
Evaporite_Volume_Fraction	Volume_Fraction	The volume fraction of evaporitic rock with respect to the total volume.
Event_Class	Type	Event classification by type
Event_Date	Date	The date of an event.
Event_Location	Location	Describes where the event took place, e.g., Well Head, Separator
Event_Subclass	Type	Event classification by Subclass
Event_Time	Time_Interval	Time of an event, such as a pick time from a waveform, expressed as the elapsed time from a chosen "zero" time.
Event_Time_0	Event_Time	Event Time 0
Event_Time_1	Event_Time	Event Time 1
Event_Time_2	Event_Time	Event Time 2
Event_Time_3	Event_Time	Event Time 3
Event_Time_4	Event_Time	Event Time 4
Execution_Date	Date	The date that a contract is executed, usually the date of signing of the last signatory
Existence_Kind	Type	Classification of the lifecycle state of an entity: actual, planned, predicted, etc.
Expansion_Factor	Indicator	A factor that accounts for the change in gas density due to pressure changes, as across an orifice.
Expected_Life	Operating_Time	Expected operating time of the equipment, generally defined as operating time of the first failure for 95% of the equipment
Expiration_Date	Date	Expiration date of a legal document or an item.
Expiry_Date	Date	The date at which a contract terminates or is no longer in force. If the expiry date is amended, this is the amended date.
Explicit_Index	Multi_Use_Property	Token, normally an integer, which is used as a reference or pointer to a value stored in some data structure.
Exponent	Data_Valued_Property	A number, normally symbolized as a superscript to a term in an expression, which indicates the power to which the term is raised.
Exposure_Class	Code	Classification of the installation location and resulting environmental risk, i.e., liquid, dust, shock,...
External_Boundary_Pressure	Pressure	The pressure existing at the external boundary of the drainage area of the well.
External_Drainage_Radius	Reservoir_Distance	The characteristic radius to the outer drainage boundary of a field or a reservoir
Extrapolated_Pressure	Pressure	Extrapolated pressure from infinite-acting analysis
Extrapolated_Pressure_Sph	Extrapolated_Pressure	Extrapolated pressure from spherical flow analysis
FIT_Equivalent_Mud_Weight	Mud_Density	Equivalent mud weight determined by the formation integrity test (FIT) for a new formation below last casing shoe via increasing the pressure until a pre-determined value.
Facies_Boundary_Type	Type	The type of a Facies Boundary in the Earth subsurface
Facies_Type	Type	The type of a Facies in the Earth subsurface
Fan_Shape	Shape	Shape of a Fan type depositional environment, i.e. Elongated or Crescent.
Fann_Test_Pressure	Pressure	The pressure at which the Fann test was performed.
Fann_Test_Temperature	Temperature	The temperature at which the Fann test was performed.
Fault_Character	Type	The characterization of a Fault in the Earth subsurface, e.g. Sealing, Non Sealing, Constant Pressure, etc.
Fault_Control_Flag	Flag	Flag marking if a layer is affected by faulting.
Fault_Detection_Source	Source	The source of the data used to detect faults (e.g., Seismic data, Structural analysis, Dipmeter log data, etc.)
Fault_Displacement	Displacement	The measure of the relative movement of the 2 sides of a fault.
Fault_Distortion_Type	Type	The type of distortion associated with a fault plane, e.g. Rollover, Drag, etc.
Fault_Hade	Plane_Angle	The angle that a fault plane makes with the vertical.
Fault_Heave	Displacement	Horizontal component of separation or displacement on a fault.
Fault_Strike	Azimuth	The azimuth of the strike of a fault.
Fault_Throw	Height	Length of the vertical displacement of a Fault.
Fault_Transmissibility	Ratio	Ratio of fault transmissibility to formation transmissibility.
Fault_Type	Type	The type of a Fault in the Earth subsurface, e.g. Normal, Hinge, Reverse, Dextral, etc.
Faulting_Time_Wrt_Sedimentation	Type	Time of faulting with respect to the sedimentation process, e.g. Post Deposition, Post Compaction, etc.
Faulting_Time_Wrt_Tilt	Type	Time of faulting with respect to tectonic events which tilted the bed, e.g. Anterior, Posterior
Fax_Number	Phone_Number	Telephone number used for FAX (facsimile) transmission and/or reception.
Feature_Dip	Dip_Angle	Dip computed on a general feature surface by measuring the difference in attribute values between two points compared to the horizontal distance between the points.
Feature_Intersection_Type	Type	Defines how a Wellbore intersects with a Geologic Feature
Feldspar_Volume_Fraction	Volume_Fraction	The volume fraction of feldspar with respect to the total volume.
Field_Name	Name	Name given to a field; may be a company-specific or regulatory name.
File_Name	Name	The name of a computer data file.
File_System_Name	Name	Name of computer operating system component which deals with data file storage, e.g. NFS (Unix), RMS (VMS).
File_Type	Type	Generic property for computer file types.
Fill_Bottom_Depth	Depth	Measured depth of the bottom of the fill. (Fill : unwanted material, formation sand, proppant, gravel pack failure, workover debris ... filling up the wellbore)
Fill_Height	Height	Height of unwanted material (formation sand, proppant, gravel pack failure, workover debris ...) filling up the wellbore
Fill_Top_Depth	Depth	Measured depth of the top of the fill. (Fill : unwanted material, formation sand, proppant, gravel pack failure, workover debris ... filling up the wellbore)
Filter_Cake_Density	Density	Density of the filter cake (mudcake).
Filter_Cake_Photoelectric_Factor	Photoelectric_Factor	Photoelectric Factor of the filter cake (mudcake); often expressed in an approximation unit barns/electron.
Filter_Cake_Resistivity	Resistivity	Resistivity of Mud Filter Cake
Filter_Cake_Thickness	Thickness	Filter cake thickness in API test
Filter_Cake_Thickness_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data representing mud filter cake thickness.
Filtered	Modifier	A filtering process has been applied to the data related to the property.
Filtrate_CaCl2_Concentration	Chemical_Concentration	Filtrate CaCl2 concentration in the water phase of Oil Based Mud
Filtrate_Viscosity	Viscosity	The viscosity of the fluid filtrate i.e the viscosity of the fluid which crossed the filtering media.
Filtrate_Volume	Volume	Volume of filtrate, such as recovered from an API Fluid Loss test. API RP13 Section 3
Final	Modifier	Not to be altered or undone.
Final_Transfer_Pressure	Pressure	Final pressure of shipping bottle
Final_Transfer_Temperature	Temperature	Final temperature of shipping bottle
Firing_Head_Type	Type	Type of TCP Equipment: firing head, debris sub, shock absorber, etc.
First_Derivative	Gradient	First derivative of a scalar function
Fishneck_Diameter	Outside_Diameter	Diameter of the fishing neck of an equipment item.
Fishneck_Length	Length	Length of the fishing neck of an equipment item.
Fissure_Storativity_Ratio	Storativity_Ratio	Ratio of fissure storativity to total system storativity. Usually known as Omega in reservoir dynamics.
Flag	Indicator	An indicator of which of two or more conditions exist, or of which option has been selected. Most flags are binary in nature with a Yes/No possibility.
Flattening	Shape	For an ellipse, the difference between the lengths of the major and minor axes divided by length of the major axis, often expressed as its inverse (Inverse_Flattening).
Flattening_Depth	Depth	Depth at which flattening should be calculated based on the flattening feature.
Flex_Joint_Angle	Plane_Angle	Angle between riser and blowout preventer at the flex joint.
Flow_Behavior_Index	Exponent	The n parameter in the Power-Law and Herschel-Bulkley rheological models. The Power_Law model is "Shear_Stress=k times (Shear_Rate at the power of n)". n is dimensionless.
Flow_Capacity	Volume_Fraction	The characteristic of a layer in a permeable system that describes the fraction of greater permeability-thicknesses for a layer with respect to the system permeability-thickness.
Flow_Direction	Type	Indicates the flowing mode of a well completion; typically Injector or Producer.
Flow_Direction_Setup	Type	Indicates the wellbore flow direction for which an equipment item has been configured.
Flow_Head_Code	Code	Code for the flow head
Flow_Head_Type	Type	Type of flow head
Flow_Regime	Type	The flow condition of a multiphase process stream; e.g. slug, mist, or stratified flow.
Flow_Type	Type	The type of flow of a fluid, e.g. Laminar, Pivot, etc.
Flow_Unit	Unit_Code	Unit for fluid flow data.
Flow_Velocity	Velocity	Flow velocity of fluid.
Flowing_Condition_Depth	Depth	Depth at which bottomhole data were acquired
Flowing_Fluid_Type	Fluid_Type	Type of fluid flowing into or out of a well completion: Condensate, Oil, Gas, etc.
Flowing_Pressure	Pressure	The pressure of the flowing well measured at the intake point in the borehole.
Flowrate	Data_Valued_Property	A measure of the volume of fluid flowing per unit time.
Flowrate_Gradient	Gradient	A measure of the change in the flowrate of a fluid per unit length.
Flowrate_Index	Flowrate	Unitless quantity proportional to flowrate within a given borehole environment. Flowrate indices are comparable only when the borehole and casing sizes are the same.
Fluid_Compressional_Slowness	Compressional_Slowness	Acoustic slowness of a fluid; the slowness of the compressional wave.
Fluid_Compressional_Velocity	Compressional_Velocity	Acoustic velocity of an acoustic (compressional) wave in fluid.
Fluid_Conductivity	Conductivity	Conductivity of a fluid.
Fluid_Contact_Type	Type	The type of fluid contact between Earth subsurface regions or volumes, e.g. Oil Water Contact, Gas Water Contact, etc.
Fluid_Density	Density	Density of a fluid sample; e.g., from Borehole, Formations, Cores, etc. Also density of cement.
Fluid_Level	Height	The level of fluid in a column or vessel, normally expressed as height above (or below) some reference point.
Fluid_Loss	Volume	The volume of drilling fluid filtrate which is obtained in a filtration test under specific test conditions; used as an indication of the expected rate of filtrate invasion into the formation during drilling.
Fluid_Marker_Type	Type	The type of a fluid marker depending on the fluid type occupying either side of the surface intersecting the borehole (e.g. Gas above Oil, Oil above Water, etc.)
Fluid_Permeability_Factor	Ratio	Fraction of the fracture permeability retained at in-situ conditions after taking into account the damage due to fluid residue, function of the breaker, gel concentration and temperature at closure. Has the same effect as Proppant_Permeability_Factor.
Fluid_Phase	Type	The phase of a fluid (gas or liquid)
Fluid_Resistivity	Resistivity	Resistivity of a fluid.
Fluid_Return_Elevation	Elevation	Elevation of the drill fluid return line measured from the defined elevation reference datum (normally kelly bushing or rig floor). Note that if the elevation is negative, the return line is below the elevation reference datum.
Fluid_Return_Outlet	Type	Location of drilling fluid outlet of the circulating system. It is normally on the rig floor at the level of mud pit. In some offshore cases (conductor) it can be on the sea bed.
Fluid_Sample_Origin	Source	General location from which a fluid sample was taken (test line, mud pit)
Fluid_Temperature	Temperature	The temperature of a fluid (sample) under certain conditions.
Fluid_Type	Type	The type of fluid. Usually associated with a formation, a reservoir, borehole, etc.
Fluid_Viscosity	Viscosity	The viscosity of a fluid (sample) at specific temperature and pressure conditions.
Fluid_Volume	Volume	Volume of fluid.
Fluorine_Yield	Elemental_Yield	Elemental contribution of Fluorine with respect to total.
Flushed_Zone_Bound_Water_Saturation	Bound_Water_Saturation	The extent to which the pore space in a flushed zone around the borehole contains bound water.
Flushed_Zone_Bound_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of bound water in the flushed zone with respect to the total volume.
Flushed_Zone_Conductivity	Conductivity	The conductivity of the zone immediately behind the mudcake and which is considered to be flushed by mud filtrate, i.e., it is considered to have all mobile formation fluids displaced from it.
Flushed_Zone_Dissolved_Salt_Volume_Fraction	Volume_Fraction	The volume fraction of dissolved salt in the flushed zone with respect to the total volume.
Flushed_Zone_Free_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of free water in the flushed zone with respect to the total volume.
Flushed_Zone_Gas_Volume_Fraction	Gas_Volume_Fraction	The volume fraction of gas in the flushed zone with respect to the total volume.
Flushed_Zone_Hydrocarbon_Volume_Fraction	Hydrocarbon_Volume_Fraction	The volume fraction of hydrocarbon in the flushed zone with respect to the total volume.
Flushed_Zone_Irreducible_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of irreducible water in the flushed zone with respect to the total volume.
Flushed_Zone_OBMF_Saturation	Saturation	The extent to which the pore space in a flushed zone around the borehole contains oil based mud filtrate.
Flushed_Zone_OBMF_Volume_Fraction	Volume_Fraction	The volume fraction of oil-based mud filtrate in the flushed zone with respect to the total volume.
Flushed_Zone_Oil_Volume_Fraction	Oil_Volume_Fraction	The volume fraction of oil in the flushed zone with respect to the total volume.
Flushed_Zone_Resistivity	Resistivity	Resistivity of the formation flushed zone (that portion of the formation in which the movable fluids are considered to have been completely replaced by mud filtrate during drilling).
Flushed_Zone_Water_Saturation	Saturation	The extent to which the pore space in a flushed zone around the borehole contains water.
Flushed_Zone_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of water in the flushed zone with respect to the total volume.
Flux_Leakage	Data_Valued_Property	The proportion of magnetic flux forced out of the pipe by the distortion of the field caused by the presence of a discontinuity
Fold_CDP	Count	Number of traces stacked at a CDP.
Fold_Type	Type	Type of fold (e.g., Rollover)
Force	Data_Valued_Property	An agency or influence that if applied to a free body results chiefly in an acceleration of the body and sometimes in elastic deformation and other effects.
Foreign_System	Type	Type of seismic system: Charisma, IESX
Format	Type	General plan of organization or arrangement, such as for a computer data file or for the presentation of data.
Formation_Compressive_Strength	Compressive_Strength	The compressive strength of an earth formation.
Formation_Conductivity	Conductivity	Formation Conductivity
Formation_Damage_Skin	Skin_Factor	The skin effect caused by mechanical or chemical formation damage such as invasion of drilling fluids, migration of fine material, wettability change, scale deposit or bacteria. The annular volume damaged is called the Damaged Zone.
Formation_Name	Name	Name given to a geologic formation; may be a local name or an accepted standard.
Formation_Resistivity	Resistivity	True Formation Resistivity
Formation_Resistivity_Factor	Ratio	Ratio of the resistivity of water-saturated rock to that of the water solution contained in the rock. Also called Formation Resistivity Factor and abbreviated "F".
Formation_Resistivity_Sw100	Resistivity	Resistivity of formation, assuming 100% water-saturated.
Formation_Stiffness_Factor	Data_Valued_Property	Dimensionless estimate of the formation stiffness, i.e., ratio between the applied pressure and the displacement of the formation.
Formation_System_Type	Type	Formation system assigned by the client
Formation_Temperature	Temperature	Temperature of the (earth) formations.
Formation_Volume_Factor	Volume_Fraction	The ratio of the volume occupied by a fluid at specified conditions, such as reservoir conditions, to the volume which would be occupied at standard conditions.
Formula	Description	Symbolic expression of a rule or principle.
Fossil_Genus	Genus	Name for genus of fossil within some group.
Fossil_Group	Group	Name for biological group of fossils.
Fossil_Species	Species	Name for species of fossil within some genus.
Fossil_Type	Type	Type of fossil (animal or plant remnant from past geological ages, preserved in the earth's crust)
Fraction_Above_Depth_Point	Ratio	Unitless fraction of an image that is displayed above the depth associated with the image.
Fractional_Surface_Area	Data_Valued_Property	The fraction of a clays specific surface area which participates in hydraulic flow.
Fracture_Azimuth	Azimuth	The azimuth of a fracture usually in an interval of the borehole.
Fracture_Bridging_Factor	Ratio	Ratio of fracture width to mean proppant diameter (Industry usage: 2.5.) below which bridging will occur (proppant cannot move through the fracture).
Fracture_Closure_Pressure	Pressure	Magnitude of the stress required to open a preexisting fracture. Assumed to be equal to the least principal stress which acts perpendicular to the face of the fracture, trying to keep it closed. Above it, the fracture is open, closed below.
Fracture_Closure_Time	Time_Interval	Time required by a hydraulic fracture to close. Can be derived from a Nolte plot (pressure vs. time). The more fluid that fluid leaks off into the formation, the faster the fracture closes.
Fracture_Condition	Type	Characterizes the condition of the fracture with respect to its void space; e.g. Open, Closed, Vuggy, etc.
Fracture_Conductivity	Conductivity	Fracture permeability - width product of a finite conductivity vertical or horizontal fracture.
Fracture_Density	Data_Valued_Property	Density of fracture occurrence, often measured as a function of linear trace length of fractures observed in a given surface area.
Fracture_Element_Distribution_Type	Type	Type of spatial variation (linear or elliptical) of fracture height, width and conductivity
Fracture_Element_Height	Height	Height of fracture element
Fracture_Element_Width	Width	Width of fracture element
Fracture_Face_Skin	Skin_Factor	The skin along the face of the fracture (natural or hydraulic).
Fracture_Geometry	Geometry	Characterizes the geometry of a fracture: Planar or Linear.
Fracture_Half_Length	Length	The length of one wing of a fracture, from the bore hole to one of its ends.
Fracture_Height	Height	Height of a fracture.
Fracture_Length	Length	The length of one wing of a fracture.
Fracture_Normal_Weakness	Ratio	The ratio of normal compliance of the fracture to the total normal compliance of the fractured rock. It indicates how much of the total compliance of the fractured rock is due to the fractures. See Compliance.
Fracture_Orientation	Azimuth	The orientation of a fracture relative to north.
Fracture_Origin	Type	Characterizes the origin of a fracture i.e. natural (inherent) or induced.
Fracture_Plausibility	Probability	Estimate of the likelihood that a given rock body is fractured.
Fracture_Pressure	Pressure	Fluid pressure in the wellbore required to undergo hydraulic fracturing.
Fracture_Pressure_Gradient	Pressure_Gradient	Ratio of the Frac Pressure to the true vertical depth. Typical values for a reservoir range from 0.4-0.6 psi/ft for a depleted reservoir to 0.8-1.0 psi/ft for deep high pressure formation.
Fracture_Pressure_Safety_Factor	Safety_Factor	Amount by which borehole pressure should remain below fracture pressure, to allow for uncertainty in fracture pressure estimation.
Fracture_Shear_Weakness	Ratio	The ratio of shear compliance of the fracture to the total shear compliance of the fractured rock. It indicates how much of the total compliance of the fractured rock is due to the fractures. See Compliance.
Fracture_Spacing	Width	The distance between adjacent fractures.
Fracture_Storativity	Storativity	Fracture Storativity (Porosity * Total Compressibility product) of a finite conductivity vertical fracture ("(phi*Ct)f")
Fracture_Toughness	Strength	Measure of the rock resistance to crack propagation (Hydraulic Fracturing). Must not be confused with tensile strength. Obtained by compressing a slice of core with a central hole. Expressed as Pressure times square root of length.
Fracture_Type	Type	Type of formation fracture.
Fracture_Width	Width	Width of a fracture.
Fracturing_Efficiency	Efficiency	Ratio of Fracture Volume at end of job to Total Volume Pumped. The difference between the two volumes represents the volume which leaked off into the formation.
Frame_Bulk_Modulus	Bulk_Modulus	The bulk modulus of the solid frame of the rock. The solid frame of the rock includes the porosity but not the content of the pore spaces.
Frame_Density	Density	Bulk density of the solid frame of the rock. The solid frame of the rock includes the porosity but not the content of the pore spaces. Frame_Density = (1 - Porosity) * Grain_Density.
Frame_Number	Ordinal_Number	Multi-source/multi-receiver shot record identifier
Frame_Shear_Modulus	Shear_Modulus	The shear modulus of the solid frame of the rock. The solid frame of the rock includes the porosity but not the content of the pore spaces.
Free_Fluid_Index	Data_Valued_Property	The proportion of the bulk volume of the formation which is occupied by fluids which are free to flow; commonly abbreviated FFI, measured using nuclear magnetic resonance techniques.
Free_Gas_Oil_Ratio	Gas_Oil_Ratio	The ratio of the volume of free gas to the volume of oil for a reservoir fluid at standard conditions.
Free_Water_Level	Depth	Depth at which the water pressure and oil/gas pressure are equal; the depth at which Pc (capillary pressure) is equal to 0.
Frequency	Data_Valued_Property	The repetition rate of a periodic waveform. The inverse of period.
Friction_Angle	Plane_Angle	Angle relating the increase in shear strength with compressive strength.
Friction_Coefficient	Ratio	Ratio of the frictional (tangential) force to the contact (normal) force between two objects or materials in contact.
From_Conn_Number	Ordinal_Number	Indicates which end (1 or 2 for tubulars, 3 for a hydraulic tee,...) of the "From" equipment is connected to the "To" equipment
From_Datum_Code	Geodetic_Datum_Code	Code of the source datum used in a datum-to-datum coordinate system transformation (datum shift).
From_Entity_Code	Entity_Code	Code of Entity from which the relationship originates.
From_Mounting_Location	Location	Location of the from Equipment in a From-To connection : Inside, Outside, Top, Bottom. If A is mounted on top of B in the borehole and if From_Id=A, To_Id=B, then From_Mouting_Location=Top. If Packer P is set inside casing C, with From_Id=P, To_Id=C then From_Mouting_Location=Inside
From_Offset	Length	The distance from the mid-point of the "From" equipment to the bottom of the "To" equipment in a From_To connection.
From_Property_Code	Property_Code	Code of Property of Entity from which the relationship originates.
Function_Name	Name	Name of a software program function.
Fundamental_Strength	Strength	The stress a material is able to withstand under a given set of conditions (temperature, pressure, solution, etc.) without deforming continuously.
Funnel_Viscosity	Viscosity	Time needed for a given quantity of fluid (generally a quart of mud) to flow into a specified size funnel (3/16 inch id tube of a 12 inch long funnel). Used for drilling fluids.
GPD_Lithology_Pattern	Name	Name of the GPD pattern used to draw the lithology.
GQI_Admission_Policy	Processing_Option	Identifies the Geometry Query Interface (GQI) policy for maintaining the content of a geometric feature as it is edited. The most common value is POINT_SET_PRESERVING, but applications may implement others so the values are not constrained.
Gadolinium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of gadolinium to total dry weight
Gadolinium_Yield	Elemental_Yield	Elemental contribution of Gadolinium with respect to total.
Gain	Data_Valued_Property	An increase in amplitude or power from one point in a system to another, such as between input and output.
Gamma_Ray	Data_Valued_Property	The intensity of natural gamma-ray radiation emitted from formations containing radioactive elements, such as Potassium, Thorium, and Uranium. Measured according to API specifications.
Gamma_Ray_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a gamma ray logging measurement.
Gamma_Ray_Minus_Uranium	Gamma_Ray	The measurement of the naturally occurring gamma radiation less the radiation attributed to uranium.
Gamma_Ray_Time_After_Bit	Time_After_Bit	In MWD/LWD logging, the time delay between the drill bit and a gamma ray sensor reaching a given point in the wellbore.
Gap_Length	Interval_Length	The length of gap usually detected in some pattern or geological feature. The length is usually an interval length like depth.
Gas_Acoustic_Velocity	Acoustic_Velocity	Sound velocity of gas at reservoir pressure and temperature. Typical value is 200 m/s.
Gas_Compressibility	Compressibility	Change in gas volume per unit volume per change in pressure (dV/V.dp) at a given pressure and temperature.
Gas_Density	Density	Density of gas (air, hydrocarbon, etc.) at a particular temperature and/or pressure; e.g., gas density at well bottomhole conditions or at well surface conditions.
Gas_Description_Type	Type	Type of data describing the gas: complete hydrocarbon composition, impurities (H2S, CO2,N2) or gas gravity.
Gas_Deviation_Factor	Coefficient	Dimensionless quantity expressing how a gas deviates from perfect gas law, commonly expressed by PV=ZnRT. Sometimes named Gas Compressibility Factor, but NOT the same as Gas_Compressibility. Z usually varies from 0.7 to 1.2.
Gas_Differential_Pressure	Differential_Pressure	Gas differential pressure across the orifice plate when a sample is taken
Gas_Flag	Flag	Flag indicating presence of gas
Gas_Flow_Velocity	Flow_Velocity	Flow velocity of gas component of fluid.
Gas_Flowrate	Flowrate	Rate of flow of gas
Gas_Fluid_Ratio	Volume_Fraction	The ratio of gas within a fluid otherwise named foam quality when the gas is used to foam the fluid.
Gas_Formation_Volume_Factor	Formation_Volume_Factor	Ratio of gas volume at specified (typically, reservoir) conditions to the gas volume at surface (stock tank) conditions. Normally abbreviated Bg.
Gas_Fraction	Volume_Fraction	Volumetric fraction of gas in the total fluid
Gas_Gravimeter_Type	Type	Type of instrument used to measure gas gravity
Gas_Gravity	Specific_Gravity	The ratio of the molecular weight of the gas to that of air
Gas_Holdup	Holdup	Volume fraction of gas in the upward-moving stream of a producing well.
Gas_Line_Diameter	Diameter	Diameter of the gas line
Gas_Line_Pressure_Gauge_Type	Type	Gauge used to measure gas meter pressure
Gas_Line_Temperature_Gauge_Type	Type	Gauge used to measure gas meter temperature
Gas_Liquid_Ratio	Volume_Fraction	Volume ratio of gas to liquid (oil + water) in a volume of fluid.
Gas_Mass_Flowrate	Mass_Flowrate	Mass flowrate of gas.
Gas_Meter_Type	Type	Type of meter used to measure gas flowrate
Gas_Metering_Line_Size	Diameter	Line size of gas meter inlet and outlet pipe
Gas_Oil_Ratio	Volume_Fraction	A measure of the volume of gas which is produced with a given quantity of oil.
Gas_Pressure_Axis_Type	Type	One of the pressure transformations used in Gas Well Interpretation
Gas_Probability	Probability	The probability that gas is present in the formation.
Gas_Sampling_Point	Location	The location where gas samples are taken on the separator
Gas_Saturation	Saturation	The extent to which the pore space in a formation contains gas.
Gas_Saturation_At_Breakthrough	Gas_Saturation	Gas saturation at the breakthrough point. In Special Core Analysis, breakthrough is the appearance of the injected fluid at the outlet face of the rock sample.
Gas_Saturation_Min_So_3Phase	Gas_Saturation	The gas saturation at minimum oil saturation in a three phase system. (SCAL SGM)
Gas_Sorption_Storativity_Ratio	Ratio	Ratio of the stored gas in the kerogen (solid hydrocarbon) to the total gas stored in the system
Gas_Viscosity	Viscosity	The viscosity of a gas at specific temperature and pressure conditions.
Gas_Volume_Fraction	Volume_Fraction	The volume fraction of gas with respect to the total volume; the product of Porosity and Gas_Saturation
Gas_Water_Contact_Depth	Depth	Depth at which the gas water contact has been identified in a Reservoir Unit
Gas_Water_Solubility	Solubility	Measure of the degree to which a gas is soluble in water, often designated Rs Water
Gauge_Count	Count	Number of gauges
Gauge_Length	Length	Length of the in-gauge portion of an equipment item.
Gauge_Pressure	Pressure	Pressure above one atmosphere.
Gel_Concentration	Concentration	Concentration of gelled fluid (fracturing gel, gelled acid ...)
Gel_Temperature	Temperature	Temperature of gelled fluid (fracturing gel, gelled acid ...)
General_Weather_Description	Description	Description of current weather conditions.
Genus	Biological_Name	A category of biological classification ranking between the family and the species. A class, kind, or group marked by one or more common characteristics.
Geocentric_Dx	Displacement	X component of the translation of the center of a geodetic datum. One of seven parameters used in the Bursa-Wolf transformation.
Geocentric_Dy	Displacement	Y component of the translation of the center of a geodetic datum. One of seven parameters used in the Bursa-Wolf transformation.
Geocentric_Dz	Displacement	Z component of the translation of the center of a geodetic datum. One of seven parameters used in the Bursa-Wolf transformation.
Geocentric_Rx	Rotation	Rotation of the geocentric Cartesian coordinate system about its X axis. One of seven parameters used in the Bursa-Wolf transformation.
Geocentric_Ry	Rotation	Rotation of the geocentric Cartesian coordinate system about its Y axis. One of seven parameters used in the Bursa-Wolf transformation.
Geocentric_Rz	Rotation	Rotation of the geocentric Cartesian coordinate system about its Z axis. One of seven parameters used in the Bursa-Wolf transformation.
Geocentric_Scale_Factor	Scale_Factor	Scale factor used in the Bursa-Wolf transformation.
Geodetic_Coord_Sys_Code	Code	Type of a geodetic coordinate system. This property specifies whether the Geodetic coordinate system used to record position data is Cartesian or Latitude/Longitude.
Geodetic_Coord_Sys_Name	Name	Name of a geodetic coordinate system.
Geodetic_Datum_Code	Code	Code of the reference system that describes the position, orientation and scale relationship of the ellipsoid and the earth, such that referenced coordinates are unique.
Geodetic_Datum_Name	Name	Name of the reference system that describes the position, orientation and scale relationship of the ellipsoid and the earth, such that referenced coordinates are unique.
Geodetic_Datum_Point	Name	Name of Origin of Geodetic Datum
Geodetic_Datum_Point_Latitude	Latitude	Latitude of Origin of Geodetic Datum
Geodetic_Datum_Point_Longitude	Longitude	Longitude of Origin of Geodetic Datum
Geographic_Location	Location	Geographical location, either the nearest city or geographical spot or a free text telling where the location is.
Geologic_Age	Absolute_Time	The geochronologic age of an item or event, such as an earth layer. This is usually the average age in millions of years (Ma).
Geologic_Age_Code	Code	Reference code of a geologic age; e.g., Paleozoic, Permian, etc. classified according to the type of geologic age unit (Era, Epoch, etc.).
Geologic_Age_Type	Type	Type of geologic age unit; e.g., Era, Period, Epoch, Age.
Geologic_Flag	Flag	Flag indicating that the object or data pertains to geology or was derived from geologic data.
Geological_Influence_Type	Type	The type of geological influence that dominates some feature such as a sedimentary channel, e.g. Wave dominated, Delta dominated, etc.
Geometric_Mean_Permeability	Permeability	Mean permeability in horizontal or vertical plane, computed as the square root of the product of the normal directional permeability values (e.g. X-Y or Y-Z) in the plane.
Geometrical_Factor	Data_Valued_Property	A geometry-dependent weighting factor used to characterize how different media in the neighborhood of a sensor participate in the sensor measurement.
Geometry	Data_Valued_Property	The geometry of an object; e.g. the geometry of an Earth formation, a Fault, a Field, a Basin, a Borehole, etc. Usually represented with a Grid, Mesh, Parametric curves, or other complex representations.
Geophone_Type	Type	Type of geophone, used to detect particle motion associated with the passage of a seismic wave.
Geopolitical_Region_Code	Code	The code/name given to a geopolitical region, e.g. Nation, State, County, Province, Community, etc.
Geopolitical_Region_Type	Type	The type of a geopolitical region, e.g. Nation, State, County, Province, Community, etc.
Geothermal_Gradient	Thermal_Gradient	The rate of change of temperature with depth in the Earth. It averages about 30 degC/km at shallow depths.
Get_Function_Name	Function_Name	Name of function used to read data.
Glauconite_Volume_Fraction	Volume_Fraction	The volume fraction of glauconite with respect to the total volume.
Gooseneck_Radius	Curvature_Radius	Radius of the gooseneck in a Coil Tubing Unit, along which the tubing is bent; used in the fatigue model
Grade	Data_Valued_Property	A rating of some sort given to an item (e.g., equipment) by some standards organization as the API, the IADC, etc.
Gradient	Data_Valued_Property	The change in the value of a quantity per unit distance in a specified direction.
Grading_Date	Date	Date on which the grading of equipment condition or state took place.
Grain_Density	Density	The density of a unit volume of a mineral or other rock material at zero porosity. Sometimes called Matrix Density.
Grain_Distribution	Description	Textual description of the grain distribution in a rock sample.
Grain_Size	Diameter	Average diameter of a mineral grain or set of grains.
Granulometric_Sequence_Type	Type	This property specifies whether the granules making up a Earth subsurface sequence are coarsening up or fining up.
Graphic_Symbol_File_Name	File_Name	Graphic symbol file specification. [In GeoFrame, this is typically a GPD file, e.g., gpd_lib/stop_symbol.gpd]
Graphic_Symbol_Name	Name	Name assigned to a graphic symbol.
Graphical_File	File_Name	Name of file containing related graphical information
Gravel_Packed_Perforation_Length	Perforation_Length	Length of the portion of the perforation which is filled with Gravel Pack material.
Gravity	Acceleration	Strength of the gravitational field at some location. Also referred to as the acceleration of gravity, measured in units of acceleration.
Gravity_Bladeface	Bladeface	In directional drilling, the angle between Top of Hole and a sensor contained in a stabilizer blade; used in hole sections of high deviation. Measurement is from -180 to +180 degrees.
Gravity_Toolface	Toolface	In directional drilling, the angle between Top of Hole and a reference direction on the drill string (e.g. Y-Axis accelerometer); used in hole sections of high deviation. Measurement is from -180 to +180 degrees.
Great_Circle_Axis	Plane_Angle	The pole to a plane represented by a great circle.
Great_Circle_Azimuth	Azimuth	The azimuth of a plane represented by a great circle.
Great_Circle_Dip	Dip_Angle	The dip of the plane represented by a great circle.
Grid_Convergence_Angle	Plane_Angle	Angle to be used in converting azimuths between true north and grid north or the Y axis of the cartographic projection. [Geoshare convention: True Azimuth = Grid Azimuth + Grid_Convergence_Angle]
Gross	Modifier	Unrefined.
Gross_Area	Surface_Area	Gross area of a region such as that of a lease parcel or covered by a lease agreement.
Gross_Cutoff_Absent_Fraction	Quality_Indicator	Fraction of the summation interval for which data to apply "Initial" cutoff criteria are unavailable; used as a coarse indicator of the reliability of the summation results.
Gross_Porosity	Porosity	The average porosity in a gross thickness interval or a group of intervals.
Gross_Thickness	Thickness	Total thickness of a zone or a collection of zones, including portions which may not be of interest; may still be subject to discriminator cutoffs specified as "Initial".
Group	Biological_Name	An assemblage of related organisms - often used to avoid taxonomic connotations when the kind or degree of relationship is not clearly defined.
Group_Velocity	Acoustic_Velocity	The velocity with which the energy in a wavetrain travels. In dispersive media, it is the velocity of the envelope of the wavetrain.
Gypsum_Volume_Fraction	Volume_Fraction	The volume fraction of gypsum with respect to the total volume.
H2S_Concentration	Chemical_Concentration	Concentration of H2S generally measured in ppm. H2S concentration is critical in evaluating the corrosion of metal (e.g. coiled tubing) under stresses.
H2S_Flag	Flag	Indicates that hydrogen sulfide (H2S) has been detected.
H2S_Mole_Fraction	Mole_Fraction	Mole fraction of Hydrogen Sulfide to total gas composition
H2S_Service_Flag	Flag	Specifies whether equipment is for H2S service or not
H2S_Service_Type	Type	Type of H2S corrosion service capability, e.g., Proof or Resistant
HGS_Concentration	Solids_Concentration	High gravity solids Concentration
HGS_Removal_Efficiency	Efficiency	Ratio of mass rate of HGS (high Gravity Solid) discarded through the underflow of a piece of SCE (Solids Control Equipment) to the mass rate of HGS fed into it
HTHP_Filter_Cake_Thickness	Filter_Cake_Thickness	Thickness of filter cake produced under high temperature, high pressure (HTHP) conditions.
HTHP_Filtrate_Volume	Filtrate_Volume	Volume of filtrate produced under high temperature, high pressure (HTHP) conditions.
Halite_Volume_Fraction	Volume_Fraction	The volume fraction of halite with respect to the total volume.
Heat	Energy	Energy that causes substances to rise in temperature, fuse, evaporate, expand, or undergo any of various other related changes.
Heat_Capacity	Data_Valued_Property	The amount of heat required to raise the temperature of a unit volume of a given material by one degree.
Heat_Exchanger_Code	Code	Code for heater used in testing and production services
Heat_Flux	Data_Valued_Property	The quantity of thermal energy which passes through a cross-sectional area per unit time.
Heat_Release_Rate	Data_Valued_Property	The quantity of heat released in a material per unit time. Also known as mixing power.
Heat_Transfer_Coefficient	Data_Valued_Property	Amount of heat transferred per unit time per degree per unit area.
Heater_Type	Type	Heater type
Heavy_Phase_Flow_Velocity	Flow_Velocity	Flow velocity of heavy phase component of fluid.
Height	Length	The distance from the bottom to the top of something standing upright. Also, the extent of elevation above a level.
Hemisphere	Type	Code of the earth hemisphere (Northern or Southern) in which this projection is located.
Heterogeneity_Cosine_Of_Phase	Reflection_Heterogenity	Measure of heterogeneity computed from the Cosine of Phase trace over a given interval.
Heterogeneity_Instantaneous_Frequency	Reflection_Heterogenity	Measure of heterogeneity computed from the Instantaneous Frequency trace over a given interval.
Heterogeneity_Instantaneous_Phase	Reflection_Heterogenity	Measure of heterogeneity computed from the Instantaneous Phase trace over a given interval.
Heterogeneity_Reflection_Strength	Reflection_Heterogenity	Measure of heterogeneity computed from the Reflection Strength trace over a given interval.
Heterogeneity_Seismic_Amplitude	Reflection_Heterogenity	Measure of heterogeneity computed from the Seismic Amplitude trace over a given interval.
Hierarchical_Flag	Flag	Flag indicating that the entities participate in a hierarchy.
High	Modifier	Of greater degree, size, amount, or content than average or ordinary. Of relatively great importance. Advanced in complexity, development, or elaboration.
Holdup	Volume_Fraction	In a producing well, the volume fraction of a specific fluid phase in the upward-moving stream. The relative quantities of fluids produced are related to the holdup and upward velocity of each phase.
Holdup_Index	Holdup	Unitless quantity proportional to holdup within a given borehole environment. Holdup indices are comparable only when the borehole and casing sizes are the same.
Hole_Azimuth	Azimuth	The angle between a vertical plane tangent to the borehole and north.
Hole_Condition_Type	Type	The type of a borehole condition.
Hole_Deviation	Deviation	Angle between the borehole axis and the vertical (also known as the Drift Angle and, in the drilling industry, Inclination).
Hole_Inside_Diameter	Inside_Diameter	The effective inside diameter of a Well; may be of the Borehole, Casing or Tubing.
Hole_Rotation_Friction_Coefficient	Friction_Coefficient	Friction coefficient between open hole and drill string in rotation
Hole_Sliding_Friction_Coefficient	Friction_Coefficient	Friction coefficient between open hole and drill string in sliding (translation only) operating mode
Hole_Translation_Friction_Coefficient	Friction_Coefficient	Vertical component of the Friction coefficient between open hole and drill string during an helical movement, e.g., reaming mode
Hook_Load	Load	The downward force exerted on the hook of the traveling block by the suspended equipment (drillstring, casing, etc.)
Horizon_Sample_Count	Count	Number of horizon samples to use while smoothing.
Horizon_Tracking_Event	Type	Type of waveform event identified by the Horizon (crossing +/-, crossing -/+, peak, trough)
Horizon_Type	Type	The type of a Horizon in the Earth subsurface, e.g. Seismic or Geological
Horizontal_Formation_Resistivity	Formation_Resistivity	Formation resistivity measured parallel to layering. (for "Transverse-Isotropic (TI)" rock"
Horizontal_Mean_Permeability	Geometric_Mean_Permeability	Geometric mean permeability in the horizontal plane (X-Y) of the reservoir.
Horizontal_Mobility	Mobility	A measure of the ease with which a fluid can be moved horizontally in a specific medium (i.e. rock). The ratio of the effective horizontal permeability and the viscosity of the fluid.
Horizontal_Permeability	Directional_Permeability	A permeability oriented horizontally along the bedding plane of the stratum. Usually abbreviated as Kx.
Horizontal_Size	Diameter	The size of any object as measured horizontally
Horizontal_Well_Flowing_Length	Length	Total Horizontal Well Flowing Length
Horizontal_Well_Standoff	Reservoir_Distance	Distance from Horizontal Well to bottom of the Hydraulic Unit
Host_Identifier	System_Identifier	Identification of a host computer system where, for example, an application is to run.
Housing_Number	Identifier	Identifying number often etched onto the housing.
Hydraulic_Diffusivity	Diffusivity	The characteristic of a rock-fluid system that describes the relationship of pressure change in time to pressure gradient. It is defined as permeability divided by the product of porosity, fluid viscosity and fluid compressibility.
Hydraulic_Drive_Pressure	Pressure	Pressure of the hydraulic fluid delivered to an Hydraulic motor
Hydraulic_Drive_Temperature	Temperature	Temperature of the hydraulic fluid delivered to an Hydraulic motor
Hydraulic_Fracture_Stage	Status	Whether the fracture is considered after closure or at the end of job.
Hydraulic_Model_Type	Type	Type of Flow Behavior for the Hydraulic Unit, including the Inner Boundary Type + Reservoir Behavior Type + Outer Boundary Type
Hydraulic_Power	Power	Power produced or available from a system due to fluid flow, such as for pumps and turbines.
Hydraulic_Unit_Top_To_Flowing_Top	Reservoir_Distance	Distance from Top of Hydraulic Unit to Top of Flowing Interval
Hydraulic_Unit_Top_To_Perforation_Top	Reservoir_Distance	Distance from Top of Hydraulic Unit to Top of Perforation
Hydrocarbon_Density	Density	Density of hydrocarbons.
Hydrocarbon_Flowrate	Flowrate	Rate of flow of hydrocarbons (oil, gas and condensate)
Hydrocarbon_Pore_Volume	Pore_Volume	The pore volume of a reservoir occupied by hydrocarbons in either the vapor or liquid phase.
Hydrocarbon_Saturation	Saturation	The fraction of pore volume filled with hydrocarbons.
Hydrocarbon_Volume_Fraction	Volume_Fraction	The volume fraction of hydrocarbon with respect to the total volume; the product of porosity and hydrocarbon saturation
Hydrogen_Index	Data_Valued_Property	The ratio of the number of hydrogen atoms per unit volume of a material to that number in pure water at 75 degF. Neutron logging response depends mainly on hydrogen index.
Hydrogen_Mole_Fraction	Mole_Fraction	Mole fraction of Hydrogen to total gas composition
Hydrogen_Yield	Elemental_Yield	Elemental contribution of Hydrogen with respect to total.
Hydrophone_Type	Type	Type of geophone, used to detect pressure changes associated with the passage of a seismic wave.
Hydrostatic_Pressure	Pressure	Pressure due to the weight of a column of liquid (formation water, drilling mud, etc.) extending from the depth of interest to the liquid level.
IADC_Code	Type	International Association of Drilling Contractor Code, used for drill bits.
IADC_Grade_Bearing_Seals	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on condition of bearing seals
IADC_Grade_Dull	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on dullness characteristics
IADC_Grade_Gauge	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on gauge
IADC_Grade_Inner_Rows	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on condition of inner rows
IADC_Grade_Location	Drill_Bit_Grade_IADC	IADC Drill Bit Grade - Location
IADC_Grade_Other	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on other characteristics
IADC_Grade_Outer_Rows	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on condition of outer rows
IADC_Grade_Reason_Pulled	Drill_Bit_Grade_IADC	IADC Drill Bit Grade based on reason for pulling bit.
IPR_Fluid_Flow_Model_Type	Type	Type of Inflow Performance Behavior for the Hydraulic Unit (Darcy, Forcheimer, Vogel, Cheng)
Id	Relation_Valued_Property	A system generated number that uniquely identifies an data item (Entity, Property, Representation, ...) within certain system imposed limitations on the uniqueness.
Ideal_Receiver_Position_0	Rectangular_Position	Idealized receiver position 0
Ideal_Receiver_Position_0_X_Coord	X_Coordinate	X-coordinate of ideal receiver position 0.
Ideal_Receiver_Position_0_Y_Coord	Y_Coordinate	Y-coordinate of ideal receiver position 0.
Ideal_Receiver_Position_0_Z_Coord	Z_Coordinate	Z-coordinate of ideal receiver position 0.
Ideal_Receiver_Position_1	Rectangular_Position	Idealized receiver position 1
Ideal_Receiver_Position_1_X_Coord	X_Coordinate	X-coordinate of ideal receiver position 1.
Ideal_Receiver_Position_1_Y_Coord	Y_Coordinate	Y-coordinate of ideal receiver position 1.
Ideal_Receiver_Position_1_Z_Coord	Z_Coordinate	Z-coordinate of ideal receiver position 1.
Ideal_Receiver_Position_2	Rectangular_Position	Idealized receiver position 2
Ideal_Receiver_Position_2_X_Coord	X_Coordinate	X-coordinate of ideal receiver position 2.
Ideal_Receiver_Position_2_Y_Coord	Y_Coordinate	Y-coordinate of ideal receiver position 2.
Ideal_Receiver_Position_2_Z_Coord	Z_Coordinate	Z-coordinate of ideal receiver position 2.
Ideal_Sample_Shift_0	Time_Interval	Fractional sample shift associated with ideal position 0
Ideal_Sample_Shift_1	Time_Interval	Fractional sample shift associated with ideal position 1
Ideal_Sample_Shift_2	Time_Interval	Fractional sample shift associated with ideal position 2
Ideal_Source_Position_0	Rectangular_Position	Idealized source position 0
Ideal_Source_Position_0_X_Coord	X_Coordinate	X-coordinate of ideal source position 0.
Ideal_Source_Position_0_Y_Coord	Y_Coordinate	Y-coordinate of ideal source position 0.
Ideal_Source_Position_0_Z_Coord	Z_Coordinate	Z-coordinate of ideal source position 0.
Ideal_Source_Position_1	Rectangular_Position	Idealized source position 1
Ideal_Source_Position_1_X_Coord	X_Coordinate	X-coordinate of ideal source position 1.
Ideal_Source_Position_1_Y_Coord	Y_Coordinate	Y-coordinate of ideal source position 1.
Ideal_Source_Position_1_Z_Coord	Z_Coordinate	Z-coordinate of ideal source position 1.
Ideal_Source_Position_2	Rectangular_Position	Idealized source position 2
Ideal_Source_Position_2_X_Coord	X_Coordinate	X-coordinate of ideal source position 2.
Ideal_Source_Position_2_Y_Coord	Y_Coordinate	Y-coordinate of ideal source position 2.
Ideal_Source_Position_2_Z_Coord	Z_Coordinate	Z-coordinate of ideal source position 2.
Identifier	Data_Valued_Property	A number, label or code given to an object in an attempt to uniquely identify it.
Idle_Time	Time_Interval	Period of time during which equipment is idle. Complement of Operating_Time.
Igneous_Volume_Fraction	Volume_Fraction	The volume fraction of igneous rock with respect to the total volume.
Illite_Volume_Fraction	Volume_Fraction	The volume fraction of illite with respect to the total volume.
Illuminance	Data_Valued_Property	The intensity of light striking a surface.
Image_Clipping_Region	Data_Valued_Property	Vector of pixel values indicating which portion of an input image is represented in a clipped output; the structure of the vector is [Offset from Top, Offset from Left, Height, Width].
Image_Origin_Azimuth	Azimuth	The azimuth of a point on an object corresponding to the origin of an image of the object (left side of core image)
Impedance	Data_Valued_Property	The measure of the ability of an object or medium to resist the flow of electric current. Impedance is a complex quantity composed of a real term (Resistance) and an imaginary term (Reactance).
Impedance_Factor	Data_Valued_Property	Impedance Factor
Implementation_Code	Code	Catalog code of the Implementation of a Representation
In_Service_Date	Date	The date on which an equipment item or product was placed in service.
Incident_Angle	Plane_Angle	The angle which the raypath of an incident ray makes with the perpendicular to the interface. In an isotropic medium, it is the same as the angle that a wavefront makes with the interface.
Inclination	Plane_Angle	The vertical angle between a line and the horizontal; has historically been used in the drilling industry to mean the angle between the borehole path and vertical (the term Hole_Deviation is preferred for this concept).
Inclination_Build_Rate	Curvature	The rate of change in inclination expressed in degrees per unit of course length.
Inclination_Error	Error	Plus or minus inclination error of sensor
Included	Flag	A flag indicating whether an object is included or excluded from the spatial extent of a containing object.
Inclusion_Proportion	Proportion	Percentage of rocks occupied by inclusions within a given depth interval
Inclusion_Type	Type	The type of inclusions in a rock e.g. pebble, nodules, etc.
Index_Type	Type	Type of index for indexed data, such as Measured Depth (MD), True Vertical Depth (TVD), etc.
Indicator	Data_Valued_Property	Property which indicates presence of some entity, occurrence or condition, or which quantifies some condition, often as a proportion of some local reference value. Often called _Factor or _Coefficient.
Inductance	Data_Valued_Property	The capability of an electric circuit to induce an electromotive force (emf) within the circuit.
Inductive_Reactance	Reactance	The component of electrical impedance due to inductance.
Inertial_Flow_Coefficient_Correlation_Type	Type	Inertial Flow Coefficient Correlation (e.g. Saucier, Firoozabadi, etc. )
Inertial_Flow_Correlation_Coef	Data_Valued_Property	Cooke's inertial fracture flow correlation coefficient (b). Empirical coefficient relating Fracture inertial flow coefficient Beta to Fracture permeability. Non RP66 Unit
Inertial_Flow_Correlation_Exponent	Data_Valued_Property	Cooke's inertial fracture flow correlation exponent (a). Empirical coefficient relating Fracture inertial flow coefficient Beta to Fracture permeability.
Inetgrated_Transit_Time	Transit_Time	Acoustic transit time computed by integrating acoustic slowness measurements (from a sonic log) over a depth interval.
Initial	Modifier	Of or relating to the beginning.
Initial_Amount	Amount	Initial amount. Usually used to quantify the initial amount of some material.
Initial_Final_Wellbore_Storage_Ratio	Ratio	Ratio of early-time (initial) to final wellbore storage factor ("Ca/C")
Initial_Gas_Oil_Ratio	Gas_Oil_Ratio	Gas-Oil Ratio at the beginning of the production.
Initial_Gas_Saturation	Gas_Saturation	Gas Saturation at the beginning of the test, experiment or production.
Initial_Gas_Volume	Volume	Volume of gas accumulated prior to the beginning of the measurement period.
Initial_In_Situ_Gas_Volume	Volume	Total volume of in situ gas in the reservoir.
Initial_In_Situ_Oil_Volume	Volume	Total volume of in situ oil in the reservoir.
Initial_Oil_Saturation	Oil_Saturation	Oil Saturation at the beginning of the test, experiment or production.
Initial_Oil_Volume	Volume	Volume of oil accumulated prior to the beginning of the measurement period.
Initial_Reservoir_Pressure	Pressure	Initial reservoir pressure, before any production or injection occurs, normally abbreviated Pi; sometimes taken as the pressure at the external boundary of the drainage area.
Initial_Reservoir_Pressure_Date	Date	Date when initial reservoir pressure data were recorded
Initial_Reservoir_Pressure_Depth	Depth	Depth reference of initial reservoir pressure
Initial_Reservoir_Pressure_Temperature	Temperature	Temperature taken when initial reservoir pressure recorded
Initial_Water_Saturation	Water_Saturation	Water Saturation at the beginning of the test, experiment or production.
Initial_Water_Volume	Volume	Volume of water accumulated prior to the beginning of the measurement period.
Injected_Fluid_Type	Fluid_Type	Type of fluid injected.
Injection_Point	Type	Indicates where a fluid is injected in the main flow e.g. Low Pressure Discharge...
Injector_Head_Weight	Weight	Weight of the injector head of a coiled tubing unit
Inlet_Connection_Size	Diameter	The connection size of the input line to the equipment
Inlet_Flowrate	Flowrate	Flow Rate at the inlet of an equipment (e.g. suction side of a pump)
Inlet_Pressure	Pressure	Pressure at the inlet of an equipment item.
Inline_Dip	Dip_Angle	Angle that a surface, e.g. a bedding or fault surface, makes with the horizontal, measured in the in-line direction.
Inner_Boundary_Condition_Type	Type	Description of the inner boundary condition for a well test model.
Inner_Outer_Storativity_Ratio	Storativity_Ratio	Radially composite system storativity ratio [inner/outer bank]
Inner_Pipe_Outside_Diameter	Outside_Diameter	Outer diameter of the inner pipe
Inside_Diameter	Diameter	Inside diameter of an entity, such as an item of drillstring equipment
Instantaneous_Amplitude	Analytic_Trace	Amplitude component of an analytic seismic trace, when decomposed into amplitude and phase components (absolute value).
Instantaneous_Frequency	Analytic_Trace	Time derivative of Instantaneous_Amplitude.
Instantaneous_Frequency_Slope	Slope	Least squares slope (gradient) of instantaneous frequency in an interval.
Instantaneous_Phase	Analytic_Trace	Phase component of an analytical seismic trace when decomposed into amplitude and phase components (Hilbert transform technique)
Instantaneous_Wavenumber	Analytic_Trace	Instantaneous frequency measured in depth domain
Integrated_Apparent_Seismic_Polarity	Integrated_Trace	The integral of the Apparent Polarity trace over a given interval
Integrated_Cosine_Of_Phase	Integrated_Trace	The integral of the Cosine Of Phase trace over a given interval
Integrated_Instantaneous_Frequency	Integrated_Trace	The integral of the Instantaneous Frequency trace over a given interval
Integrated_Reflection_Strength	Integrated_Trace	The integral of the Reflection Strength trace over a given interval
Integrated_Seismic_Amplitude	Integrated_Trace	The integral of the Seismic Amplitude trace over a given interval.
Integrated_Seismic_Magnitude	Integrated_Trace	The integral of the absolute value of the Seismic Amplitude trace over a given interval.
Integrated_Slowness	Acoustic_Travel_Time	Total acoustic travel time over a wellbore interval as computed by integrating acoustic slowness from a sonic log (Compressional_Slowness) over the interval.
Integrated_Trace	Amplitude	The integral of an instantaneous attribute over a given interval.
Inter_Bed_Contrast	Conductivity_Contrast	Conductivity ratio between adjacent beds
Interfacial_Tension	Data_Valued_Property	The tension between two interfaces; e.g., light and heavy fluid phases, gas-liquid, gas-oil, gas-water. Also called surface tension or surface tensity
Interfault_Angle	Plane_Angle	The smallest angle between two intersecting sealing faults in a wedge well test model.
Intermediate	Modifier	Middle; being or occurring at the middle place or degree or between extremes.
Intermediate_Time_Level	Time_Interval	Seismic line dependent adjustment to achieve a continuous, line independent reference surface
International_Aircraft_Regulation	Code	International Aircraft Transportation Regulation pertaining to this type of Battery, e.g., IATA 3090 Cargo Only
Internet_Address	System_Identifier	Address by which a particular computer system may be reached over the Internet.
Interpolation_Method	Method_Type	Interpolation method used in the generation of data.
Interporosity_Flow_Coefficient	Indicator	Describes the conductance of flow from matrix to fissures. Usually known as Lambda in reservoir dynamics.
Interpretation_Grid_Count	Count	Number of Interpretation grids that exist for the horizon.
Interpretation_Origin	Source	Specify where interpretation was performed on data.
Interruption_Type	Type	The type of interruption in the Earth subsurface, e.g. Missing Section, Repeat Section, etc.
Interval_Alkhalifah_Eta	Alkhalifah_Eta	Interval value of Alkhalifah's eta anisotropy parameter, describing the relationship between horizontal and moveout Compressional velocities, for each layer.
Interval_Anisotropic_Axis_1_Crossline_Direction	Anisotropic_Axis_1_Crossline_Direction	Estimation of the anisotropic axis 1 crossline direction for a layer.
Interval_Anisotropic_Axis_1_Inline_Direction	Anisotropic_Axis_1_Inline_Direction	Estimation of the anisotropic axis 1 inline direction for a layer.
Interval_Anisotropic_Axis_2_Crossline_Direction	Anisotropic_Axis_2_Crossline_Direction	Estimation of the anisotropic axis 2 crossline direction for a layer.
Interval_Anisotropic_Axis_2_Inline_Direction	Anisotropic_Axis_2_Inline_Direction	Estimation of the anisotropic axis 2 inline direction for a layer.
Interval_Bale_Kappa	Bale_Kappa	Interval value of Bale's kappa, the mode-converted wave equivalent to eta, describing the relationship between horizontal and moveout Converted wave velocities, for each layer.
Interval_Bale_Xi	Bale_Xi	Interval value of Bale's xi, the shear wave equivalent to eta, describing the relationship between horizontal and moveout shear wave velocities, for each layer.
Interval_Compressional_Shear_Velocity_Ratio	Compressional_Shear_Velocity_Ratio	Value of compressional-shear velocity ratio in interval
Interval_Crossline_Dip	Crossline_Dip	Estimation of the crossline dip for a layer.
Interval_Density	Density	Interval value of the material density (density for a layer).
Interval_Inline_Dip	Inline_Dip	Estimation of the inline dip for a layer.
Interval_Length	Length	The length of an interval along a path, such as a Borehole path.
Interval_Mode_Converted_Velocity	Mode_Converted_Velocity	Converted-wave velocity measured over a finite interval, with the interval usually determined by geologic layering. The converted wave velocity is determined from the time taken for the energy to travel in one direction as Compressional wave and in the other as Shear.
Interval_Polarization_Azimuth	Polarization_Azimuth	Estimation of the polarization azimuth angle for a layer.
Interval_Porosity	Porosity	Interval value of the material Porosity (Porosity for a layer).
Interval_Q_Ratio	Q_Ratio	Interval value of the compressional wave quality factor.
Interval_Qs_Ratio	Qs_Ratio	Interval value of the shear wave quality factor.
Interval_Sayers_Anellipticity	Sayers_Anellipticity	Interval value of Sayers' normalized anellipticity factor an alternative to eta for describing the relationship between horizontal and moveout compressional velocities, for each layer.
Interval_Schoenberg_Ellipticity	Schoenberg_Ellipticity	Interval value of Schoenberg's ellipticity factor, for each layer.
Interval_Shear_Compressional_Velocity_Ratio	Shear_Compressional_Velocity_Ratio	Value of shear-compressional velocity ratio in interval
Interval_Shear_Velocity	Shear_Velocity	Interval shear wave velocity, measured over a finite interval, with the interval usually determined by geologic layering.
Interval_Thomsen_Delta	Thomsen_Delta	Interval value of Thomsen's delta anisotropy parameter, describing the relationship between vertical and moveout Compressional velocities, for each layer.
Interval_Thomsen_Epsilon	Thomsen_Epsilon	Interval value of Thomsen's epsilon anisotropy parameter, describing the relationship between vertical and horizontal Compressional velocities, for each layer.
Interval_Thomsen_Gamma	Thomsen_Gamma	Interval value of Thomsen's gamma anisotropy parameter, describing the relationship between Horizontally polarized Shear (SH) velocities in the vertical and horizontal directions, for each layer.
Interval_Thomsen_Sigma	Thomsen_Sigma	Interval value of Thomsen's sigma anisotropy parameter, describing the relationship between Vertically polarized Shear (SV) velocities in the vertical direction and moveout SV velocity, for each layer.
Interval_Time	Time_Interval	The time difference between two reflection events. It may vary due to velocity changes in different media, or changes in thickness of strata, or changes following erosion or structural deformation.
Interval_Transit_Time	Data_Valued_Property	The travel time of a wave over a unit distance, hence the reciprocal of wave velocity.
Interval_Velocity	Avg_Acoustic_Velocity	Average velocity in a layer or between two subsurface points; generally applied to a rock layer whose velocity can be considered homogeneous. May be derived from stacking velocity using the Dix equation (or a more refined variant).
Interval_Velocity_Ellipticity_Azimuth	Velocity_Ellipticity_Azimuth	Estimation of the velocity ellipticity azimuth angle for a layer
Interval_Velocity_Ellipticity_Flattening	Velocity_Ellipticity_Flattening	Estimation of the velocity ellipticity flattening for a layer.
Interwell_Distance	Reservoir_Distance	Inter-well distance for a horizontal interference test
Interwell_Storativity_Thickness	Storativity_Thickness	Inter-well Storativity-Thickness [phiCth] for a horizontal interference test.
Intrinsic_Safety_Certification_Marking	Annotation	Mark made on an equipment item defining the type of intrinsic certification. Typical marking includes certifying authority symbol, type of protection, protection group for electrical apparatus and temperature class, e.g., "EEx ia I T5": CENELEC Intrinsic Safety-2 faults Methane 100 degree C.
Intrinsic_Safety_Flag	Flag	When set, indicates that the equipment has been certified for use in a hazardous area. Equipment so certified has been examined by a National Certifying Authority and, where necessary, tested and found to comply with the requirement of a standard specification for the appropriate concept.
Invasion_Annulus_Resistivity	Resistivity	Resistivity of the invasion annulus, a region of the formation lying between the flushed zone and the undisturbed formation, and filled with interstitial water displaced from the flushed zone.)
Invasion_Diameter	Diameter	The diameter to which drilling mud filtrate has invaded porous and permeable rock around the borehole.
Invasion_Radius	Radius	The radius of the "invaded zone", the region in which drilling mud filtrate has invaded porous and permeable rock around the borehole.
Inverse_Flattening	Shape	Inverse of the flattening of an ellipse.
Inverse_Penetration_Rate	Data_Valued_Property	Inverse of drilling penetration rate.
Investigation_Radius	Radius	The radius of a circle (or cylinder) which has the primary influence on a measurement; material or objects outside the Investigation_Radius have little or no effect on the measurement.
Investigation_Radius_Increase	Length	Increase of candidate borehole investigation radius
Iron_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of iron to total dry weight
Iron_Yield	Elemental_Yield	Elemental contribution of Iron with respect to total.
Irreducible	Modifier	Impossible to bring into a desired, normal, or simpler state
Irreducible_Water_Saturation	Saturation	The fraction of the pore volume occupied by water in a reservoir at maximum hydrocarbon saturation, such that it cannot be further reduced.
Irreducible_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of water which remains after flushing with hydrocarbon, with respect to the total volume.
Isolated_Porosity_Volume_Fraction	Volume_Fraction	The volume fraction of isolated porosity with respect to the total volume.
Issue_Number	Identifier	Issue (e.g. Volume,number) of a periodical publication
Item_Code	Code	Code reference to an item.
J_Function	Function_Name	Name of the J Function, a function used to normalize capillary pressure to account for differences in permeability, porosity, and fluid systems.
J_Function_Coeff	Coefficient	Coefficients used in the J function, a function used to normalize capillary pressure to account for differences in permeability, porosity, and fluid systems.
Jar_Operating_Time	Operating_Time	Operating time of the jar over the reporting period.
Job_Count	Count	Number of jobs performed or included.
Job_Number	Identifier	Reference number assigned to a job or service
Joint_Count	Count	The number of joints of tubular goods.
Journal_File	File_Name	File that maintains process history, i.e., the chain of actions performed on the object.
KB_Receiver_Correction	Correction	Correction vector to receiver position relative to Kelly Bushing
KB_Receiver_Dx	X_Coordinate	X coordinate of correction vector to receiver position relative to Kelly Bushing.
KB_Receiver_Dy	Y_Coordinate	Y coordinate of correction vector to receiver position relative to Kelly Bushing.
KB_Receiver_Dz	Z_Coordinate	Z coordinate of correction vector to receiver position relative to Kelly Bushing.
KB_Source_Correction	Correction	Correction vector to source position relative to Kelly Bushing
KB_Source_Dx	X_Coordinate	X coordinate of correction vector to source position relative to Kelly Bushing.
KB_Source_Dy	Y_Coordinate	Y coordinate of correction vector to source position relative to Kelly Bushing.
KB_Source_Dz	Z_Coordinate	Z coordinate of correction vector to source position relative to Kelly Bushing.
Kaolinite_Volume_Fraction	Volume_Fraction	The volume fraction of kaolinite with respect to the total volume.
Kick_Pressure	Pressure	Pressure measurement used for kick detection.
Kick_Tolerance_Volume	Volume	Estimate of the volume of a kick (influx of fluid into the wellbore) at bottom hole conditions which can be shut in and circulated out without breaking the formation
Kill_Line_Pressure	Pressure	Pressure observed at kill line/BOP.
Kinematic_Viscosity	Viscosity	The dynamic viscosity of a fluid divided by the density of the fluid.
Klinkenberg_Factor	Coefficient	Empirical conversion factor used to estimate Klinkenberg permeability from measured gas permeability.
Klinkenberg_Permeability	Absolute_Permeability	Empirical permeability measure derived by extrapolating the trend of gas permeability versus inverse pressure to infinite pressure (zero inverse pressure). The result is equivalent to the permeability which would be measured if the sample were 100% saturated with a non-reactive liquid and is sometimes called "liquid permeability" and abbreviated KL (where L is a subscript).
Kurtosis	Statistical_Property	A measure of the sharpness of a population distribution. If X10, X25, X75 and X90 are the values for which 10, 25, 75, and 90 percent of the population is smaller, respectively, then kurtosis = (X75 - X25) / 2(X90 - X10).
LGS_Concentration	Solids_Concentration	Low gravity solid Concentration
LGS_Removal_Efficiency	Efficiency	Ratio of the mass rate of LGS (low gravity solid) in the underflow of a piece of SCE (Solids Control Equipment) to the mass rate of LGS fed into it
LOT_Equivalent_Mud_Weight	Mud_Density	Equivalent mud weight determined by the leak off test (LOT) for a new formation below last casing shoe via increasing the pressure until the formation starts taking fluid.
LTLP_Filter_Cake_Thickness	Filter_Cake_Thickness	Thickness of filter cake produced under low temperature, low pressure (LTLP) conditions.
LTLP_Filtrate_Volume	Filtrate_Volume	Volume of filtrate produced under low temperature, low pressure (LTLP) conditions.
LWD_Operating_Time	Operating_Time	Operating time of the logging-while-drilling (LWD) equipment over the reporting period.
LWD_Tool_Type	Tool_Type	The type of a tool used for Logging While Drilling.
Lag_Usage_Flag	Flag	When set, wavelet lag is used.
Landing_Collar_Depth	Depth	Measured depth of the collar on which the cement plugs seat : this data is required to compute the displacement volume of a cementing operation.
Language	Name	Name of spoken or written language, such as English, Spanish, French, Mandarin, Russian, Chichimeq...
Last_Calibration_Date	Date	Date when a sensor was last calibrated
Last_Static_Pressure_Depth	Depth	Depth at which last reservoir pressure data were recorded
Last_Static_Reservoir_Pressure	Pressure	Last reservoir pressure recorded
Latent_Heat	Heat	The amount of thermal energy required to convert an unit mass of liquid at its boiling point to completely vapor.
Latitude	Plane_Angle	The angle between the axis of the Earth and a tangent to the ellipsoid which approximates the shape of the Earth.
Latitude_Longitude_Unit	Unit_Code	Unit for Latitude and Longitude data.
Layer_Diffusivity	Diffusivity	Diffusivity (permeability divided by the product of porosity, fluid viscosity and fluid compressibility) for a reservoir layer.
Layer_Storativity_Ratio	Ratio	Ratio of layer storativity to total storativity ("omegaj")
Layer_Transmissibility_Ratio	Ratio	Ratio of layer transmissibility to total transmissibility ("kappaj")
Lead_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of lead to total dry weight
Lead_Yield	Elemental_Yield	Elemental contribution of Lead with respect to total.
Leakoff_Height	Height	Portion of the zone fracturing fluids will leakoff into. It can be an aggregate of a number of geologic formations.
Lease_Name	Name	Name of a lease
Lease_Status	Status	Status of a lease.
Lease_Suffix	Name	Suffix associated with lease (e.g., OCS-G)
Left_Hidden_Width	Width	For core images, the width of the core which is hidden on the left side of the image (by core box, for example).
Legal_Datum	Geodetic_Datum_Code	Code of legislated geodetic datum
Legal_Description	Description	Legal description associated with a legal document or agreement, for instance, a description of the boundaries of a lease.
Legal_Ellipsoid	Ellipsoid_Code	Code of legislated geodetic ellipsoid.
Legal_Projection	Projection_Code	Code of legislated map projection method.
Length	Data_Valued_Property	Linear extent of a measured distance or dimension.
Length_Cocked	Length	Length of an equipment item such as a mechanical jar in cocked position
Length_Compressed	Length	Length of an equipment item such as a mechanical jar in compressed position
Length_Extended	Length	Length of an equipment item such as a mechanical jar in extended position
Length_Recovered	Length	Length of a sample recovered from some well operation (e.g. Core Sample).
Length_Uncertainty	Uncertainty	Uncertainty of a Length measurement.
Length_Unit	Unit_Code	Unit for Length data
Lessor_Bonus	Money	Bonus payed to lessor for signing
Level_Count	Count	Number of levels in a sequence or portion of a sequence, such as in a hierarchy.
Level_Number	Ordinal_Number	Identifier of a particular level in a sequence; used by GeoFrame as an auxiliary depth identifier.
Library_Doc_File	File_Name	Name of file containing documentation for (software) library.
Light_Phase_Flow_Velocity	Flow_Velocity	Flow velocity of light phase component of fluid.
Lime_Concentration	Chemical_Concentration	Lime content in water based mud as determined per API RP13P Section 8
Line_Style	Type	Line drawing style, such as pattern of dots and dashes.
Line_Thickness	Type	Line drawing width or thickness
Line_Type	Type	The type of an Earth curvilinear object, e.g. the line along the intersection of 2 subsurface horizons.
Linear_Thermal_Expansion	Indicator	The change in length of a material as a fraction of its total length due to a change in temperature at a constant pressure.
Linear_Weight	Weight	Weight of an equipment item per unit length; e.g. Casing weight, pipe weight, cable weight, etc.
Liquid_Flow_Velocity	Flow_Velocity	Flow velocity of liquid component of fluid.
Liquid_Flowrate	Flowrate	Rate of flow of liquid.
Liquid_Formation_Volume_Factor	Formation_Volume_Factor	Ratio of total liquid volume at specified (typically, reservoir) conditions to the total liquid volume at surface (stock tank) conditions.
Liquid_Gas_Ratio	Volume_Fraction	Volume ratio of liquid (oil + water) to gas in a volume of fluid.
Liquid_Head_Pressure	Hydrostatic_Pressure	Pressure, represented as the height of a column of dense fluid that can be supported by the pressure.
Liquid_Radius	Length	Liquid radius in the Bowl = Bowl Inner Radius - Pond_Depth
Liquid_Saturation	Saturation	The fraction of the total pore volume in a formation or rock sample occupied by liquid.
Liquid_Viscosity	Viscosity	The viscosity of a liquid at specific temperature and pressure conditions.
Litho_Density	Bulk_Density	Formation density as measured with a Litho-Density or Gamma-Gamma type logging tool; conventionally abbreviated RHOB.
Litho_Description	Description	Textual description of the lithology.
Litho_Gross_Thickness_Ratio	Ratio	Ratio of Litho_Thickness to Gross_Thickness of a reservoir summation interval.
Litho_Penetration_Rate	Data_Valued_Property	The rate at which a drill bit penetrates a particular lithostratigraphic layer; measured in units of time per mass.
Litho_Pressure	Pressure	The pressure produced by the weight of overlying rock. Also called Abnormal pressure.
Litho_Thickness	Thickness	Total thickness for given lithology in a reservoir summation interval.
Litho_Type	Type	The classification of lithology in a stratified environment, e.g. Carbonate, Shale, Sand, etc.
Lithologic_Color	Color	The characteristic color of a lithologic sample.
Live_Trace_Flag	Flag	Indicator if trace is live or dead.
Load	Force	The load (down or up) exerted on some object; e.g., hook load.
Load_Date	Date	Date data was loaded
Loaded_By	Person_Name	Name of person who loaded data
Local_Coord_Sys_Code	Code	Catalog Code of a locally defined coordinate system.
Local_Coord_Sys_Name	Name	Name of a local coordinate system.
Local_Paleo_Shoreline_Orient	Orientation	The orientation of a shoreline pertaining to the local paleontology.
Location	Data_Valued_Property	The location of any Earth, Region, Equipment, or other entities relative to a coordinate system.
Log_Flag	Flag	Flag indicating the presence of a log, or that an item or event is to be included in a log.
Logger_Elevation_Reference_Code	Code	Code of the elevation reference for logging data
Logger_Total_Depth	Total_Depth	The total depth of the well borehole as reported by the logging contractor.
Logging_Cable_Flag	Flag	Y/N: tells if there is a wireline cable inside the tubing allowing logging
Logging_Unit	Serial_Number	Serial number of the logging unit.
Long_Term_Stability	Data_Valued_Property	Stability over the long term
Longitude	Plane_Angle	Angle measured about the spheroid (or ellipsoid) axis from a local prime meridian to the meridian through the point. A positive value denotes East.
Longitude_Reference_1	Longitude	Latitude of first reference point in projection definition.
Longitude_Reference_2	Longitude	Latitude of second reference point in projection definition.
Longitudinal_Amplitude	Amplitude	Amplitude of the longitudinal component in multi-component seismic.
Longitudinal_Dispersivity_Coefficient	Coefficient	A coefficient used as a multiplier of interstitial velocity to estimate dispersion in the direction of movement for a displacement front in permeable media.
Longitudinal_Relaxation_Time	Relaxation_Time	Longitudinal, or spin-lattice, relaxation time constant for alignment rate of nuclei to static magnetic field; normally abbreviated by symbol T1.
Loss_On_Ignition	Concentration	Proportion by weight of a sample which remains after the sample has been heated (e.g. 1000 degC) in an oxygen atmosphere and the volatile oxides evaporated.
Loss_On_Ignition_H2O_Plus	Concentration	Volatile Hydrogen component of Loss On Ignition, sometimes abbreviated H2O+.
Lost_Time_Flag	Flag	Flag indicating whether or not an event caused a delay in operation.
Low	Modifier	Of lesser degree, size, or amount than average or ordinary. Small in number or amount.
Low_Power_Flag	Flag	Flag indicating whether or not the tool is operating in low power consumption mode. When the flag is set, the sensor warmup duration is taken into account.
Lower_Fluid_Type	Fluid_Type	The type of fluid found in the layer below a reference surface (e.g. Water in layer below a Fluid Contact in a Reservoir.)
Lower_Surface_Relation	Type	The type of relationship between a surface and the ones below (e.g. the surfaces below a Horizon are eroded).
Luminous_Flux	Data_Valued_Property	Rate of flow of visible-wavelength radiant energy, as measured from a point source and within a unit solid angle.
Luminous_Intensity	Data_Valued_Property	The density of luminous flux per unit solid angle, measured in a given direction relative to the emitting source.
MRE_Latitude_Coefficient	Coefficient	Coefficient for a latitude term in a multiple regression equation for computing geodetic datum shifts.
MRE_Longitude_Coefficient	Coefficient	Coefficient for a longitude term in a multiple regression equation for computing geodetic datum shifts.
MSL_Receiver_Correction	Correction	Correction vector to receiver position relative to Mean Sea Level.
MSL_Receiver_Dx	X_Coordinate	X coordinate of correction vector to receiver position relative to Mean Sea Level.
MSL_Receiver_Dy	Y_Coordinate	Y coordinate of correction vector to receiver position relative to Mean Sea Level.
MSL_Receiver_Dz	Z_Coordinate	Z coordinate of correction vector to receiver position relative to Mean Sea Level.
MSL_Source_Correction	Correction	Correction vector to source position relative to Mean Sea Level.
MSL_Source_Dx	X_Coordinate	X coordinate of correction vector to source position relative to Mean Sea Level.
MSL_Source_Dy	Y_Coordinate	Y coordinate of correction vector to source position relative to Mean Sea Level.
MSL_Source_Dz	Z_Coordinate	Z coordinate of correction vector to source position relative to Mean Sea Level.
MWD_DPoint	Data_Valued_Property	Integer representation of MWD/LWD data as transmitted from the downhole tool.
MWD_Data_Density	Density	Density of data samples per length of borehole traversed; may be expressed as samples per unit length or as a Boolean indicator of sample presence within a depth frame.
MWD_Operating_Time	Operating_Time	Operating time of the MWD equipment over the reporting period.
MWD_Tool_Code	Code	Specific code of a tool used for Measurement While Drilling.
MWD_Tool_Type	Tool_Type	The type of a tool used for Measurement While Drilling.
Magnesium_Concentration	Chemical_Concentration	Magnesium concentration in a material.
Magnesium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of magnesium to total dry weight
Magnesium_Yield	Elemental_Yield	Elemental contribution of Magnesium with respect to total.
Magnetic_Bladeface	Bladeface	In directional drilling, the angle between Magnetic North and a sensor contained in a stabilizer blade; Measurement represents an Azimuth, with values from 0 to 360 degrees.
Magnetic_Declination	Azimuth	The horizontal angle measured from a meridian to the direction of magnetic north as determined by a freely suspended magnet. Positive if magnetic North is east of True North.
Magnetic_Declination_Date	Date	Effective date and time at which the magnetic declination value has become valid.
Magnetic_Declination_Source	Source	Name of a declination survey, a vendor of declination data, a reference book, or a person supplying the value.
Magnetic_Field_Strength	Data_Valued_Property	The force per unit magnetic pole (or current per unit length). Also called Magnetizing Force or Magnetic Intensity.
Magnetic_Flux	Data_Valued_Property	The flux through a surface is the integral over the surface of the normal component of the magnetic induction.
Magnetic_Flux_Density	Data_Valued_Property	A vector quantity symbolized by B and given in terms of the force produced on a small element of length which is carrying an electric current. B relates to the magnetizing force by a constant called the Magnetic Permeability.
Magnetic_Inclination	Inclination	The vertical angle measured between the horizontal plane and the direction of magnetic north as determined by a freely suspended magnet. Sometimes known as magnetic dip. Positive values if the direction to magnetic north is below the horizon.
Magnetic_Permeability	Data_Valued_Property	The three-dimensional inductance of a material, a measure of the magnetic induction produced in a material by a given magnetic field strength. Free space (and nonmagnetic rock) has a permeability of 1.257*10-6 henrys/meter.
Magnetic_Susceptibility	Data_Valued_Property	A measure of the degree to which a substance may be magnetized; the ratio of the magnetization to the magnetic field strength.
Magnetic_Toolface	Toolface	In directional drilling, the angle between North and a reference direction on the drill string (e.g. Y-Axis accelerometer); used in hole sections of low deviation. Measurement represents an Azimuth, with values from 0 to 360 degrees.
Magnetization	Data_Valued_Property	A measure of the effect of the medium on the magnetic field, B, when subject to a magnetizing force, H; B = Mu0 * (H + M), where Mu0 is the permeability of free space.
Magnitude	Data_Valued_Property	Absolute value of Amplitude.
Major_Axis	Diameter	Length of the major (long) axis of an ellipse.
Major_Axis_Azimuth	Azimuth	Major axis Azimuth of the ellipse of uncertainty (related parameter: EOU_MAJOR_AXIS_AZIM)
Major_Component	Name	The major component of a composition (e.g. the major component of a chemical product)
Major_Dimension	Length	Major (normally longer) dimension of an object; the actual type of measurement depends upon the shape of the object. [Used for Drilling Targets, whose shapes could be Elliptical, Circular, Rectangular...]
Mandatory	Flag	Flag indicating if a relationship is mandatory or optional for the referencing object.
Manganese_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of manganese to total dry weight
Manganese_Yield	Elemental_Yield	Elemental contribution of Manganese with respect to total.
Manual_Control_Flag	Flag	Flag indicating whether the activity is/was controlled manually by the user (1) or automatically by the system or application (0)
Manufacturer	Organization_Code	The unique code of the manufacturer, usually a company or organization code.
Map_File	File_Name	Name of file containing standard map.
Map_Migrated_Depth	Depth	Depth obtained through map migration of time surface data
Map_Modeled_Time	Two_Way_Time	Two-way time obtained through map modeling of depth surface data
Map_Scale	Ratio	The ratio of a distance measured on a map to the actual distance. It is normally expressed as a unitless ratio (e.g. 1:1000), or as the product of a unitless ratio and the ratio of two units (e.g. 1 in = 5 mile, or .2 in/mi).
Map_Scale_Factor	Scale_Factor	The ratio of the scale along the meridian or along the parallel at a given point to the scale at some map point or along some line; each point on the map has a distinct value.
Mass	Data_Valued_Property	The property of a body that is a measure of its inertia, that is commonly taken as a measure of the amount of material it contains, that causes a body to have weight in a gravitational field.
Mass_Flowrate	Data_Valued_Property	A measure of flow rate expressed as mass of material per unit time.
Mass_Fraction	Ratio	The ratio of the mass of a component to the total mass.
Mass_Spectrum_Abundance	Amount	The abundances of the molecular constituents of a material; may be represented as voltage of a flame ionization detector, amount relative to a standard solution or actual mass quantities.
Material_Addition_Count	Count	Number of packaging units of chemicals added to the drilling fluid. (e.g., Add 5 sacks of Barite C100 100lb/sack to the drilling fluid)
Material_Addition_Depth_Increment	Interval_Length	The depth increment at which the material addition takes place (e.g., Add 5 sacks of Barite C100 100lb/sack to the drilling fluid each 500 ft)
Material_Code	Code	Catalog code of material.
Material_Phase	Type	The physical state or phase of a material, such as Liquid or Solid.
Material_Type	Type	The type or class of materials both naturally occurring or used in some activity, e.g. Hydrocarbon, Mineral, Rock, Steel, Proppant, etc.
Material_Weight	Mass	Weight of Material
Matrix_Block_Skin	Skin_Factor	Matrix to natural fracture skin factor in a naturally fractured system.
Matrix_Compressibility	Compressibility	The compressibility of a homogeneous solid material.
Matrix_Compressional_Slowness	Compressional_Slowness	Acoustic slowness of a compressional wave in a given material or matrix.
Matrix_Compressional_Velocity	Compressional_Velocity	Acoustic velocity of a compressional wave in a given material or matrix.
Matrix_Electromagnetic_Propagation_Time	Electromagnetic_Propagation_Time	The time it takes for an electromagnetic wave to traverse a fixed distance of a given material or matrix. In this case the material or matrix is a specific, zero porosity rock, e.g. sandstone, limestone or dolomite.
Matrix_Epithermal_Neutron_Porosity	Epithermal_Neutron_Porosity	Matrix response of an epithermal neutron porosity logging device.
Matrix_Neutron_Capture_Cross_Section	Neutron_Capture_Cross_Section	The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of the rock matrix for the capture of neutrons.
Matrix_Photoelectric_Factor	Photoelectric_Factor	Photoelectric Factor of the matrix (zero-porosity rock) or pure material; often expressed in an approximation unit barns/electron.
Matrix_Shear_Slowness	Shear_Slowness	Acoustic slowness of a shear wave in a given material or matrix.
Matrix_Shear_Velocity	Shear_Velocity	Acoustic velocity of a shear wave in a given material or matrix.
Matrix_Specific_Gravity	Specific_Gravity	Specific gravity of the rock matrix. Typical value is 2.7 .
Matrix_Thermal_Neutron_Porosity	Thermal_Neutron_Porosity	Matrix response of a thermal neutron porosity logging device.
Matrix_Volume	Volume	The volume of material in a porous system that does not include the volume of the pores.
Matrix_Volumetric_Photoelectric_Factor	Volumetric_Photoelectric_Factor	Matrix identification indicator computed from bulk density and Photoelectric Factor; often expressed in an approximation unit barns/cc.
Max_Allowable_Flowrate	Flowrate	Maximum allowable flowrate for the equipment
Max_Allowable_Pressure	Pressure	Maximum allowable pressure for the equipment
Max_Allowable_Surface_Pressure	Pressure	Maximum allowable mud surface pressure in annulus (drill-pipe x casing) to be used during well control operations so as not to exceed the FIT/LOT equivalent mud weight.
Max_Amount	Amount	Maximum Quantity
Max_Amplitude	Amplitude	Maximum value of amplitude
Max_Bend_1_Angle	Bend_1_Angle	Maximum first bent angle
Max_Bend_2_Angle	Bend_2_Angle	Maximum second bent angle
Max_Bend_Angle	Plane_Angle	Maximum bend angle range available, as in a bent sub.
Max_Borehole_Diameter	Borehole_Diameter	Maximum borehole diameter
Max_Calibrated_Value	Multi_Use_Property	Maximum value of the range for which the equipment is calibrated.
Max_Casing_Inside_Diameter	Inside_Diameter	Maximum inside diameter of casing for which service or equipment is suitable
Max_Concentration_1	Concentration_1	Maximum concentration or proportion of first component
Max_Concentration_2	Concentration_2	Maximum concentration or proportion of second component
Max_Concentration_3	Concentration_3	Maximum concentration or proportion of third component
Max_Concentration_4	Concentration_4	Maximum concentration or proportion of fourth component
Max_Data_Set_Count	Count	Maximum number of Data Set
Max_Delay_Time	Delay_Time	Maximum Delay Time
Max_Density	Density	Maximum density
Max_Depth	Depth	Maximum Depth
Max_Differential_Pressure	Differential_Pressure	Maximum Differential Pressure
Max_Down_Load	Load	Maximum down load for an equipment item such as a drilling jar (lower limit of shock/cushion load.)
Max_Element_Count	Element_Count	Maximum number of elements in a group or collection.
Max_Extreme_Time	Time_Interval	Maximum time at extreme conditions
Max_Flowrate	Flowrate	Maximum flowrate
Max_Gamma_Ray	Gamma_Ray	Maximum value of Gamma Ray
Max_Gas_Flowrate	Gas_Flowrate	Maximum gas flowrate
Max_Gauge_Count	Count	Maximum number of Gauges possible with this type of Equipment
Max_Gooseneck_Pressure	Pressure	Maximum pressure observed during a Coil Tubing job at the goose neck
Max_Hole_Deviation	Hole_Deviation	Maximum deviation value of the wellbore from the vertical
Max_Hydraulic_Power	Hydraulic_Power	Maximum hydraulic power (Flowrate x pressure) of a fluid. Often referred to Hydraulic horse power
Max_Inclination	Inclination	Maximum inclination of sensor
Max_Index	Multi_Use_Property	Generalized maximum value of index, typically distance or time.
Max_Lift_Load	Load	Maximum lift load
Max_Magnitude	Magnitude	Maximum magnitude.
Max_Manifold_Choke_Size	Inside_Diameter	Maximum inner diameter of the choke orifice
Max_Mud_Density	Mud_Density	Maximum allowable mud density
Max_Oil_Flowrate	Oil_Flowrate	Maximum oil flowrate
Max_Operating_Pressure	Pressure	Maximum pressure which an equipment can withstand without permanent damage at standard temperature.
Max_Operating_Temperature	Temperature	Maximum operating temperature for an equipment item.
Max_Outer_Vessel_Pressure	Pressure	Maximum working pressure of the outer equipment
Max_Outside_Diameter	Outside_Diameter	Maximum outside diameter of an equipment item.
Max_Pressure	Pressure	Maximum pressure
Max_Rig_Heave	Rig_Heave	Maximum amplitude of the vertical motion of the rig
Max_Sequence_Count	Count	Maximum Sequence Count
Max_Shale_Volume_Fraction	Volume_Fraction	Maximum value of Shale/Clay volume fraction
Max_Storage_Temperature	Temperature	Maximum Storage Temperature
Max_Surge_Pressure	Pressure	Maximum pressure to which this Equipment can be exposed for a short time without permanent damage; the Equipment will again perform to specifications when the pressure is reduced below the maximum working pressure.
Max_Surge_Temperature	Temperature	Maximum Temperature to which this Equipment can be exposed for a short time without permanent damage; the Equipment will again perform to specifications when the Temperature is reduced below the maximum working temperature.
Max_Temperature	Temperature	Maximum temperature
Max_Temperature_Reached	Temperature	Maximum temperature reached by the system, sensor or equipment
Max_Tension	Tension	Maximum tension
Max_Thickness	Thickness	Maximum thickness, as for a reservoir unit.
Max_Threshold	Threshold	Maximum threshold value.
Max_Tool_Speed	Tool_Speed	Maximum service speed allowed for, or attained by, a logging tool.
Max_Up_Pull	Force	Maximum up pull for an equipment item, such as drilling jars (upper limit of shock/cushion load).
Max_Voltage	Electric_Potential	Maximum Voltage
Max_Volume	Volume	The maximum volume not to be exceeded for a container (Tank, Mud Pit)
Max_Water_Flowrate	Water_Flowrate	Maximum water flowrate
Max_Water_Pressure	Pressure	Maximum water pressure
Max_Water_Saturation	Water_Saturation	Maximum value of Water Saturation
Max_Weight_On_Bit	Weight_On_Bit	Maximum weight on bit
Max_Working_Pressure	Working_Pressure	Recommended maximum pressure at which equipment can be used
Max_Working_Temperature	Working_Temperature	Recommended maximum temperature at which equipment can be used
Max_X	X_Coordinate	Maximum X Coordinate for region
Max_Y	Y_Coordinate	Maximum Y Coordinate for region
Maximum	Modifier	The greatest quantity or value attainable or attained. An upper limit allowed by authority. The largest of a set of numbers.
Mean_Particle_Diameter	Diameter	Average diameter of the particle (e.g. for Gravel pack sand 20/40 mean diameter=0 .025 inc/0.635 mm, 40/60 mean diameter=0.014 inch/0.355mm).
Measure_Point_Offset	Length	Distance from the Measure Point to the Reference Plane for the assembly or tool; a positive value indicates that the Measure Point is above the Reference Plane.
Measure_Reference_Plane_Offset	Length	Distance from the Measure Reference Plane to the bottom of the Equipment (which is for a tool practically the make-up line of the bottom connection). The Measure Reference Plane allows recording of the location of the sensor measure point in an equipment composition. The measure point is positioned by a length called Measure_Point_Offset, a property of the composition to which the sensor belongs. The Measure_Point_Offset is the distance from the measure reference plane of the part, i.e., sensor or tool, to the measure reference plane of the whole, i.e., tool or tool string.
Measured	Modifier	Metrical. Estimated or appraised by a criterion.
Measured_Depth	Depth	Depth measured along the borehole path from the working datum.
Mechanical_Skin	Skin_Factor	Sum of Completion_Skin, Formation_Damage_Skin including anything limiting the flow across the completed interval. Does not include Partial_Completion_Skin.
Median	Modifier	Being in the middle or in an intermediate position.
Medium_Conductivity	Conductivity	The conductivity which represents a measurement made approximately two to three feet into the formation; generally considered to measure the formation where it contain fluids which are a mixture of mud filtrate, connate water and possibly hydrocarbons.
Medium_Induction_Conductivity	Medium_Conductivity	The conductivity, made by an induction log, which represents a measurement made approximately two to three feet into the formation.
Medium_Induction_Resistivity	Medium_Resistivity	The resistivity, made by an induction log, which represents a measurement made approximately two to three feet into the formation.
Medium_Lateral_Resistivity	Medium_Resistivity	Resistivity measurement using a "lateral" electrode arrangement with a "medium" investigation radius (~a foot or two into the formation).
Medium_Laterolog_Conductivity	Medium_Conductivity	The conductivity, measured by a laterolog (or guard log) resistivity device, which represents a measurement made approximately two to three feet into the formation.
Medium_Laterolog_Resistivity	Medium_Resistivity	The resistivity, measured by a laterolog (or guard log) resistivity device, which represents a measurement made approximately two to three feet into the formation.
Medium_Resistivity	Resistivity	The resistivity which represents a measurement made approximately two to three feet into the formation; generally considered to measure the formation where it contain fluids which are a mixture of mud filtrate, connate water and possibly hydrocarbons.
Memory_Guard_Flag	Flag	Flag indicating whether or not a memory guard (memory saving mechanism which decreases the acquisition rate above 80% memory usage) option was selected.
Memory_Size	Data_Valued_Property	Memory Size, generally expressed in kilobytes or Megabytes
Memory_Type	Type	Memory Type, e.g., EEPROM, RAM ...
Memory_Usage	Ratio	Ratio of memory used to total memory.
Mercury_Saturation	Saturation	The fraction of the total pore volume in a rock sample occupied by mercury (special core analysis)
Merge_Strategy	Type	Strategy for merging data, such as into a waveform gather.
Metamorphic_Volume_Fraction	Volume_Fraction	The volume fraction of metamorphic rock with respect to the total volume.
Method	Name	Name of method used, such as in acquiring or processing data.
Method_Type	Type	The type of method used in an analysis activity in the lab or other type of activities at the wellsite. For example: chemical treatment methods.
Mf_Titration_Volume	Volume	Amount of 0.02 normal (N/50) standard sulfuric acid required in order to turn the color of methyl orange indicator solution from yellow to pink when determining methyl orange alkalinity of the mud filtrate, Mf, API RP13 Section 8, Chemical Analysis.
Micro_Conductivity	Conductivity	A measurement of the conductivity of the formation within the first few inches of the borehole wall.
Micro_Cylindrically_Focused_Resistivity	Micro_Resistivity	A measurement of the resistivity of the formation, by a cylindrically focused tool, within the first few inches of the borehole wall.
Micro_Inverse_Resistivity	Micro_Resistivity	Micro Resistivity measurement using an "inverse" lateral electrode arrangement; traditionally combined with Micro Normal Resistivity in a Microlog survey for identifying permeable beds.
Micro_Lateral_Resistivity	Micro_Resistivity	Resistivity measurement using a "lateral" electrode arrangement with a very shallow investigation radius (1-2 inches into the formation).
Micro_Laterolog_Conductivity	Micro_Conductivity	A measurement of the conductivity of the formation, by a laterolog (or guard log) resistivity device, within the first few inches of the borehole wall.
Micro_Laterolog_Resistivity	Micro_Resistivity	A measurement of the resistivity of the formation, by a laterolog (or guard log) resistivity device, within the first few inches of the borehole wall.
Micro_Normal_Resistivity	Micro_Resistivity	Micro Resistivity measurement using a "normal" electrode arrangement; traditionally combined with Micro Inverse Resistivity in a Microlog survey for identifying permeable beds.
Micro_Resistivity	Resistivity	A measurement of the resistivity of the formation within the first few inches of the borehole wall.
Micro_Spherically_Focused_Conductivity	Micro_Conductivity	A measurement of the conductivity of the formation, by a spherically focused tool, within the first few inches of the borehole wall.
Micro_Spherically_Focused_Resistivity	Micro_Resistivity	A measurement of the resistivity of the formation, by a spherically focused tool, within the first few inches of the borehole wall.
Migrated_Time_Interpretation	Time_Interpretation	Seismic travel time interpretation based on migrated sections; typically represented as a grid.
Migration_Velocity	Acoustic_Velocity	Velocity applied in seismic migration.
Min_Allowable_Flowrate	Flowrate	Minimum allowable flowrate for the equipment
Min_Amount	Amount	Minimum quantity, number of items.
Min_Amplitude	Amplitude	Trace min amplitude
Min_Borehole_Diameter	Borehole_Diameter	Minimum borehole diameter
Min_Calibrated_Value	Multi_Use_Property	Minimum value of the range for which the equipment is calibrated.
Min_Casing_Inside_Diameter	Inside_Diameter	Minimum inside diameter of casing for which service or equipment is suitable
Min_Compress_Outside_Diameter	Outside_Diameter	Minimum compressed outside diameter, such as for a centralizer.
Min_Concentration_1	Concentration_1	Minimum concentration or proportion of first component
Min_Concentration_2	Concentration_2	Minimum concentration or proportion of second component
Min_Concentration_3	Concentration_3	Minimum concentration or proportion of third component
Min_Concentration_4	Concentration_4	Minimum concentration or proportion of fourth component
Min_Delay_Time	Delay_Time	Minimum Delay Time
Min_Density	Density	Minimum density
Min_Depth	Depth	Minimum Depth of Activity
Min_Element_Count	Element_Count	Minimum number of elements in a group or collection.
Min_Flowrate	Flowrate	Minimum flowrate
Min_Gas_Flowrate	Gas_Flowrate	Minimum gas flowrate
Min_In_Situ_Stress	Stress	Formation minimum principal stress, the smallest of the 3 components of the diagonal stress tensor (fractures will propagate perpendicular to its direction). Can be defaulted to Frac Gradient x TVD. Can be output from DataFRAC treatment.
Min_Index	Multi_Use_Property	Generalized minimum value of index, typically distance or time.
Min_Inside_Diameter	Inside_Diameter	Minimum inside diameter of an equipment item.
Min_Magnitude	Magnitude	Minimum magnitude
Min_Net_Thickness	Thickness	It is common in an interbedded reservoir for sands thinner than a certain cutoff thickness (Min_Net_Thickness) to be discarded as non net or non pay in a ResSum type analysis. However, a thick sand may have two closely spaced shale stringers, such that they create the effect of a thin sand separated from thick sands above and below by thin shale beds. In this case, if the shale beds are thinner than a second thickness threshold (Min_Non_Net_Thickness), the thin sand would be counted as net or pay.
Min_Non_Net_Thickness	Thickness	It is common in an interbedded reservoir for sands thinner than a certain cutoff thickness (Min_Net_Thickness) to be discarded as non net or non pay in a ResSum type analysis. However, a thick sand may have two closely spaced shale stringers, such that they create the effect of a thin sand separated from thick sands above and below by thin shale beds. In this case, if the shale beds are thinner than a second thickness threshold (Min_Non_Net_Thickness), the thin sand would be counted as net or pay.
Min_Oil_Flowrate	Oil_Flowrate	Minimum oil flowrate
Min_Oil_Saturation_3Phase	Oil_Saturation	Minimum oil saturation in a 3 phase system. (SCAL SORM)
Min_Outside_Diameter	Outside_Diameter	Minimum outside diameter of an equipment item.
Min_Permeability	Permeability	Minimum value of Permeability
Min_Porosity	Porosity	Minimum value for Porosity
Min_Scan_Time	Time_Interval	Scan Time corresponding to the fastest scanning rate supported by the Equipment
Min_Storage_Temperature	Temperature	Minimum Storage Temperature
Min_Thickness	Thickness	Minimum thickness, as for a reservoir unit. Also used for stress calculation with coiled tubing, with data supplied by the manufacturer
Min_Threshold	Threshold	Minimum threshold value.
Min_Voltage	Electric_Potential	Minimum Voltage
Min_Water_Flowrate	Water_Flowrate	Minimum water flowrate
Min_Working_Temperature	Working_Temperature	Recommended minimum temperature at which equipment can be used
Min_X	X_Coordinate	Minimum X Coordinate for region
Min_Y	Y_Coordinate	Minimum Y Coordinate for region
Mineral_Class	Type	The classification of a mineral.
Mineral_Code	Code	Catalog-controlled code of a mineral.
Mineral_Concentration	Volume_Fraction	Volume of a particular mineral per unit volume of the investigated material, such as a sample.
Mineral_Conductivity	Conductivity	Mineral Conductivity
Mineral_Density	Density	The density of a mineral.
Mineral_Group	Type	The group to which a mineral belongs.
Mineral_Hardness	Data_Valued_Property	The hardness of a rock sample expressed in units of the MOH reference standard.
Mineral_Number	Ordinal_Number	Index in the cumulative mineral array which are naturally indexed and not indexed by Zone_Number.
Mineral_Resistivity	Resistivity	Mineral Resistivity
Minimum	Modifier	The least quantity assignable, admissible, or possible. The least of a set of numbers
Minor_Axis	Diameter	Length of the minor (short) axis of an ellipse.
Minor_Dimension	Length	Minor (normally shorter) dimension of an object; the actual type of measurement depends upon the shape of the object. [Used for Drilling Targets, whose shapes could be Elliptical, Circular, Rectangular...]
Minus_Tolerance	Tolerance	Amount of negative tolerance on a measurement value; the unit quantity is determined by that of data value.
Mis_Tie_Phase_Correction	Phase_Shift	Phase correction to apply to line to compensate for differences in Tie_Point_Phase_Shift
Mis_Tie_Phase_Time_Equivalent	Time_Interval	Equivalent time correction corresponding to the phase corrections. Assumes a specified dominant frequency.
Mis_Tie_Static_Time_Correction	Time_Interval	Constant time correction to apply to a seismic line to compensate for time differences.
Mis_Tie_Variable_Time_Correction	Time_Interval	Time correction applicable to each trace on a seismic line.
Mixing_Order	Ordinal_Number	Order in which the materials are added together. This order matters e.g. the acid is poured into the water and not the contrary, the water to the flour ...
Mixture_Type	Type	Qualifier to determine if a component is a pure chemical or a mixture of other chemicals.
Mobility	Data_Valued_Property	The measure of the ease with which a fluid can be moved in a specific medium (i.e. rock). The ratio of the effective permeability and the viscosity of the fluid.
Mobility_Ratio	Ratio	Ratio of the mobility of one system or layer (permeability divided by viscosity) to that of another system or layer.
Mode_Converted_Velocity	Acoustic_Velocity	Converted-wave velocity corresponding to a Compressional wave traveling in one direction and a Shear wave traveling the opposite direction, with conversion at the reflector.
Model_Fit_Error	Statistical_Property	Generic property for a measure of how well the actual data fit a model of the expected values and/or distribution of data. Standard measures include Standard Deviation, Variance, Chi-Square.
Model_Input_Measurement	Unit_Quantity_Code	Input measurement (Unit Quantity) for a calibration or computation model
Model_Input_Unit	Unit_Code	Input unit for a calibration or computation model
Model_Name	Name	Name of a model or version of some entity; for equipment, it may coincide with the trade name.
Model_Output_Measurement	Unit_Quantity_Code	Output Measurement (Unit Quantity) for a calibration or computation model
Model_Output_Unit	Unit_Code	Output unit for a calibration or computation model
Model_Year	Date	The year or full date of a model usually of an equipment item.
Modified_By	Person_Name	Name of person who modified data
Modifier	Property	A modifier is a property that is used to qualify another property (data or relation valued); e.g., Calibrated, Corrected, Computed, Average, etc.
Modify_Date	Date	Date of modification of a data item in the database.
Module_State	Status	Indicates the execution status of a module, such as Running, Aborted, etc.
Module_Weight	Weight	Module Weight
Molar_Concentration	Concentration	The ratio of the number of moles of a material in a sample to the volume of the sample.
Mole_Fraction	Concentration	The ratio of the number of moles of a component to the total number of moles present.
Molecular_Weight	Data_Valued_Property	Ratio of the mass of a molecule of a substance to 1/12 of the mass of a Carbon12 atom; calculated as the sum of the atomic weights of the constituent atoms.
Money	Data_Valued_Property	Amount of money; should be associated with a unit of currency.
Monophasic_Fluid_Flag	Flag	Indicates if the fluid is monophasic
Monotonic_Flag	Flag	Flag indicating that the data increase or decrease monotonically along their index. A monotonic function is one whose value either never increases or never decreases as the independent variable increases.
Montmorillonite_Volume_Fraction	Volume_Fraction	The volume fraction of illite with respect to the total volume.
Morpho_Type	Type	The classification of rocks from their internal morphology i.e., lamination thickness, inclusion size, etc.
Motor_Operating_Time	Operating_Time	Operating time of the motor over the reporting period.
Motor_Speed	Angular_Velocity	The rotational speed of a motor.
Moved_Hydrocarbon_Volume_Fraction	Hydrocarbon_Volume_Fraction	The volume fraction of moved hydrocarbons with respect to the total volume; moved hydrocarbons are those which have been displaced from the flushed zone by the invasion process.
Mud_Background_Gas_Factor	Gas_Fraction	Drill fluid background gas content as output by the chromatograph in circulating conditions.
Mud_Chloride_Concentration	Concentration	Concentration of chlorides in mud.
Mud_Compressional_Slowness	Fluid_Compressional_Slowness	Acoustic compressional slowness (Delta-T) of the drilling fluid.
Mud_Connection_Gas_Factor	Gas_Fraction	Drill fluid gas content spike as output by the chromatograph after stopping circulation in order to make or break connections.
Mud_Density	Density	The density of mud, or drilling fluid, used during drilling operations.
Mud_Filtrate_Methyl_Orange_Alkalinity_Mf	Alkalinity	The volume ratio of 0.02 normal (N/50) standard sulfuric acid (Mf_Titration_Volume) including that amount required for the Pf endpoint (Pf_Titration_Volume) to mud filtrate, API RP13 Section 8, Chemical Analysis.
Mud_Filtrate_Phenolphthalein_Alkalinity_Pf	Alkalinity	The volume ratio of 0.02 normal (N/50) standard sulfuric acid (Pf_Titration_Volume) to mud filtrate volume, API RP13 Section 8, Chemical Analysis.
Mud_Filtrate_Resistivity	Resistivity	Resistivity of Mud Filtrate
Mud_Filtrate_Volume_Per_Length	Volume_Per_Length	The measure of volume of mud filtrate lost to the formation per linear length of borehole, usually given in U.S. gal/ft.
Mud_Flowrate	Flowrate	The rate at which mud, or drilling fluid, is being pumped into, or output from, a borehole or some storage unit.
Mud_Nitrate_Concentration	Concentration	Concentration of nitrates in mud.
Mud_Phenolphthalein_Alkalinity_Pm	Alkalinity	The volume ratio of 0.02 normal (N/50) standard sulfuric acid (Pm_Titration_Volume) to mud volume in API Mud Phenolphthalein Alkalinity test (API RP13 Section 8, Chemical Analysis).
Mud_Pressure_Gradient	Pressure_Gradient	The Mud density expressed in pressure gradient. Usually used to compare the mud induced pressure with the pore and frac pressure.
Mud_Pump_Discharge_Pressure	Pressure	Mud pump maximum discharge pressure
Mud_Pump_Monitoring_Purpose	Type	The purpose of the mud pump monitoring. It can be either for well control or monitoring the pump parameters at working conditions.
Mud_Pump_Output	Mud_Flowrate	Mud pump maximum output, measured in terms of the rate of amount or mud output.
Mud_Pump_Power	Hydraulic_Power	Mud pump input horse power.
Mud_Pump_Type	Type	The type of pump used to pump drilling fluid or mud, usually into the borehole during drilling operations.
Mud_Resistivity	Resistivity	Resistivity of Drilling Fluid, also known as mud.
Mud_Temperature	Fluid_Temperature	The temperature of a mud or drilling fluid (sample) under certain conditions.
Mud_Trip_Gas_Factor	Gas_Fraction	Bottom hole drill fluid gas content spike as output by the chromatograph after stopping circulation for a significant time interval such as when tripping into the hole.
Mud_Type	Type	Type of mud used
Mudcake_Membrane_Stiffness	Data_Valued_Property	Characterization of the flexibility of mudcake, defined as the ratio of the stress difference across the mudcake-formation boundary to the relative displacement between the pore fluid and the solid frame.
Multi_Comp_Compressional_Angle	Plane_Angle	The angle between the vector perpendicular to the wave front, and the amplitude vector of the seismic defined by the X,Y and Z components. Seabed compressional velocity used.
Multi_Comp_Magnitude	Magnitude	Magnitude of multi component seismic
Multi_Comp_Shear_Angle	Plane_Angle	The angle between the vector perpendicular to the wave front and the amplitude vector of the seismic defined by the X,Y and Z components. Seabed shear velocity used.
Multi_Intersection_Flag	Flag	Flag to indicate that two geometric objects have more than one intersection; for example a wellbore may intersect a geologic feature more than once, due to the geometry of the wellbore path or that of the geologic feature.
Multi_Use_Property	Data_Valued_Property	Property whose meaning can only be interpreted within the context of its use; for example, the meaning of Max_Value requires a context to determine a type of measurement.
Multi_Valued_Flag	Flag	Boolean indicating if the Horizon has multiple Z values for a single X,Y location.
Muscovite_Volume_Fraction	Volume_Fraction	The volume fraction of muscovite with respect to the total volume.
Mute_Taper_Length	Element_Count	Number of samples muted in the traces
N2_Concentration	Chemical_Concentration	Concentration of Nitrogen
N2_Foam_Quality	Ratio	Ratio volume of N2 over foam volume . Indicator of the quality of a foam generated with N2 for well treatment. Below 50% the foam is not stable, above 95% the foam changes to a mist.
NMR_Amplitude_Distribution	Data_Valued_Property	Distribution of nuclear magnetic resonance amplitudes for different values of transverse relaxation time (T2); normally represented as a waveform of amplitude values indexed by T2 components.
NMR_Diffusion_Coefficient	Data_Valued_Property	In nuclear magnetic resonance analysis, the measure of the ability of the molecule containing the polarized proton to diffuse (or move) through a medium.
NMR_Fitting_Error	Error	Error in NMR window sum or raw echo fitting.
NMR_Permeability	Permeability	Formation permeability as measured with an nuclear magnetic logging device.
NMR_Porosity	Apparent_Porosity	Apparent formation porosity as measured with an nuclear magnetic logging device.
NMR_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from a nuclear magnetic resonance logging device.
NMR_T2_Distribution	Volume_Fraction	Distribution of volume fractions for different values of transverse relaxation time (T2); normally represented as a waveform of volume fraction values indexed by T2 components.
NRM_Factor	Coefficient	NRM factor
Name	Data_Valued_Property	The name given to any object or data item, e.g. Name of Well, Name of Field, etc.
Namespace_Code	Code	Code of a Namespace across which object names are unique.
Naming_System	Type	Name of the system which controls the valid or legal names of entities. For example, there are numerous system for naming wells: API 12 digit, CPA, Tobin
Nascent	Modifier	The most primitive data recovered in the data acquisition process. Such data and their indices are usually unscaled and are thus only usable by dedicated acquisition processing software.
Negative	Modifier	Less than zero and opposite in sign to a positive number that when added to the given number yields zero.
Negative_Slope	Multi_Use_Property	Negative slope value.
Negative_Threshold	Threshold	Negative threshold value.
Neighborhood	Type	A topological property indicating whether a spatial object lies to the "left" or to the "right" of a neighboring object whose orientation sense has been specified.
Net	Modifier	Excluding all tare. Final.
Net_Cutoff_Absent_Fraction	Quality_Indicator	Fraction of the summation interval for which data to apply "Net" cutoff criteria are unavailable; used as a coarse indicator of the reliability of the summation results.
Net_Fracturing_Pressure	Pressure	Hydraulic pressure exerted on a formation during a fracturing job (fracture pressure) minus Closure Pressure.
Net_Gross_Thickness_Ratio	Ratio	Ratio of Net_Thickness to Gross_Thickness
Net_Load	Load	Weight Indicator load minus any extra equipment weight (Injector head, Hook...)
Net_Pay_Clay_Volume_Fraction	Clay_Volume_Fraction	Average clay volume fraction in the net pay portion of the zone interval (thickness weighted arithmetic average).
Net_Pay_Cutoff_Absent_Fraction	Quality_Indicator	Fraction of the summation interval for which data to apply "Net_Pay" cutoff criteria are unavailable (including the fraction for which "Net" or "Net_Reservoir" criteria are unavailable); used as a coarse indicator of the reliability of the summation results.
Net_Pay_Flushed_Zone_Water_Saturation	Flushed_Zone_Water_Saturation	Average flushed zone water saturation in the net pay portion of the zone (thickness weighted arithmetic average).
Net_Pay_Gross_Thickness_Ratio	Ratio	Ratio of Net_Pay_Thickness to Gross_Thickness
Net_Pay_HC_Porosity_Thickness	Thickness	Total Net Pay hydrocarbon porosity-thickness for all zones; that portion of Net_Pay_Porosity_Thickness which is hydrocarbon-filled.
Net_Pay_Moved_HC_Porosity_Thickness	Thickness	The net pay moved hydrocarbon volume multiplied by the net pay thickness; the portion of Net Pay Porosity Thickness filled with moved hydrocarbons.
Net_Pay_Moved_HC_Volume_Fraction	Moved_Hydrocarbon_Volume_Fraction	Net pay moved hydrocarbon volume fraction: moved oil saturation (Sxo-Sw) in the net pay of the zone multiplied by the net pay average porosity.
Net_Pay_Permeability	Permeability	Average permeability in the net pay portion of the zone interval (thickness weighted arithmetic average).
Net_Pay_Permeability_Thickness	Permeability_Thickness	Thickness of the permeable net pay portion of the zone i.e., the product of the Net Pay Thickness and Net Pay Average Permeability
Net_Pay_Porosity	Porosity	Average Porosity of the levels which satisfy "pay zone" criteria; such criteria typically include cutoffs for clay content, porosity, water saturation and permeability.
Net_Pay_Porosity_Thickness	Thickness	Total net pay porosity-thickness of the zone interval: the product of Net Pay Thickness and Net Pay Average Porosity
Net_Pay_Thickness	Thickness	The cumulative thickness of hydrocarbon bearing rocks which satisfy local criteria for a "pay zone"; the footage which satisfies the Net Reservoir conditions and where the water saturation cutoff, permeability cutoff and any discriminator cutoffs specified as "Net Pay" are satisfied; abbreviated "H" for a Hydraulic Unit.
Net_Pay_Water_Saturation	Water_Saturation	Average water saturation in the net pay portion of the zone (thickness weighted arithmetic average).
Net_Reservoir_Clay_Volume_Fraction	Clay_Volume_Fraction	Average volume fraction of clay in the Net Reservoir portion of the zone (thickness weighted arithmetic average).
Net_Reservoir_Core_Grain_Density_Point_Match	Grain_Density	Average grain density in the Net Reservoir portion of the summation interval, computed from core data by point-match method.
Net_Reservoir_Core_Permeability_Point_Match	Permeability	Average permeability in the Net Reservoir portion of the summation interval, computed from core data by point-match method.
Net_Reservoir_Core_Porosity_Point_Match	Porosity	Average porosity in the Net Reservoir portion of the summation interval, computed from core data by point-match method.
Net_Reservoir_Core_Water_Saturation_Point_Match	Water_Saturation	Average water saturation in the Net Reservoir portion of the summation interval, computed from core data by point-match method.
Net_Reservoir_Cutoff_Absent_Fraction	Quality_Indicator	Fraction of the summation interval for which data to apply "Net_Reservoir" cutoff criteria are unavailable (including the fraction for which "Net" criteria are unavailable); used as a coarse indicator of the reliability of the summation results.
Net_Reservoir_Flushed_Zone_Water_Saturation	Flushed_Zone_Water_Saturation	Average flushed zone water saturation in the net reservoir portion of the zone (thickness weighted arithmetic average).
Net_Reservoir_Gross_Thickness_Ratio	Ratio	Ratio of Net_Reservoir_Thickness to Gross_Thickness
Net_Reservoir_HC_Porosity_Thickness	Thickness	Total Net Reservoir hydrocarbon porosity-thickness for all zones; that portion of Net_Reservoir_Porosity_Thickness which is hydrocarbon-filled.
Net_Reservoir_Log_Grain_Density_Point_Match	Grain_Density	Average grain density in the Net Reservoir portion of the summation interval, computed from log data by point-match method.
Net_Reservoir_Log_Permeability_Point_Match	Permeability	Average permeability in the Net Reservoir portion of the summation interval, computed from log data by point-match method.
Net_Reservoir_Log_Porosity_Point_Match	Porosity	Average porosity in the Net Reservoir portion of the summation interval, computed from log data by point-match method.
Net_Reservoir_Log_Water_Saturation_Point_Match	Water_Saturation	Average water saturation in the Net Reservoir portion of the summation interval, computed from log data by point-match method.
Net_Reservoir_Permeability	Permeability	Average permeability in the net reservoir portion of the zone interval (thickness weighted arithmetic/geometric/harmonic average).
Net_Reservoir_Permeability_Thickness	Permeability_Thickness	The product of the Net Reservoir Thickness and Net Reservoir Average Permeability.
Net_Reservoir_Porosity	Porosity	Average porosity in the Net Reservoir portion of the zone (thickness weighted arithmetic average).
Net_Reservoir_Porosity_Thickness	Thickness	Total pore thickness of the zone; i.e. the product of Porosity and Net_Reservoir_Thickness.
Net_Reservoir_Thickness	Thickness	Total thickness of the portion of the zone which has porosity suitable to be a potential reservoir; i.e. the footage which satisfies the Net Thickness conditions and where the porosity cutoff and any discriminator cutoffs specified as "Net Reservoir" are satisfied.
Net_Reservoir_Water_Saturation	Water_Saturation	Average water saturation in the net reservoir portion of the zone (thickness weighted arithmetic average).
Net_Shale_Thickness	Thickness	Difference between Gross_Thickness and Net_Thickness; i.e. the thickness of the formations excluded from "Net" due to cutoff for maximum clay content.
Net_Thickness	Thickness	Total thickness of the non-shales in the interval; i.e. total footage where the clay volume cutoff and any discriminator cutoffs specified as Net are satisfied.
Neutron_Capture_Cross_Section	Data_Valued_Property	The effective area within which a neutron passes in order to be captured by an atomic nucleus. Commonly called Sigma.
Neutron_Capture_Cross_Section_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from a neutron capture cross section survey.
Neutron_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a neutron logging measurement.
Neutron_Diffusion_Length	Length	Average straight-line distance a neutron travels at thermal energy levels before being absorbed by a formation nucleus.
Neutron_Porosity	Apparent_Porosity	Porosity as measured with an neutron logging device.
Neutron_Porosity_Dolomite	Neutron_Porosity	Porosity derived from a neutron logging measurement, assuming that the rock matrix material is dolomite.
Neutron_Porosity_Limestone	Neutron_Porosity	Porosity derived from a neutron logging measurement, assuming that the rock matrix material is calcite.
Neutron_Porosity_Sandstone	Neutron_Porosity	Porosity derived from a neutron logging measurement, assuming that the rock matrix material is quartz.
Neutron_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from a neutron survey.
Neutron_Slowing_Down_Length	Length	Average straight-line distance a neutron travels in being slowed from natural source energy to epithermal energy levels by collisions with formation nuclei.
Neutron_Time_After_Bit	Time_After_Bit	In MWD/LWD logging, the time delay between the drill bit and a neutron sensor reaching a given point in the wellbore.
Newtonian_Viscosity	Viscosity	Slope of Shear Stress/Shear Rate curve for the Newtonian rheology model (Shear Stress proportional to Shear Rate)
Next_Receiver_Group_Distance	Length	For non-equidistant receiver groups, distance to next group
Nickel_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of nickel to total dry weight
Nickel_Yield	Elemental_Yield	Elemental contribution of Nickel with respect to total.
Nitrogen_Mole_Fraction	Mole_Fraction	Mole fraction of Nitrogen to total gas composition
Nitrogen_Yield	Elemental_Yield	Elemental contribution of Nitrogen with respect to total.
Node_Locked_Flag	Processing_Option	A Y/N flag indicating whether a particular Node is locked and cannot be displaced.
Node_Type	Type	The type of (topological) Node, as used in the Region submodel.
Noise_Amplitude	Amplitude	The amplitude of noise or unwanted portion of a signal.
Noise_Coefficient	Coefficient	Noise coefficient of pressure sensor
Noise_To_Signal_Ratio	Ratio	The ratio of noise amplitude to signal amplitude, usually expressed in dB. Note: the inverse, Signal_To_Noise_Ratio, is preferred and should be used whenever possible.
Nom_Borehole_Diameter	Borehole_Diameter	Nominal inside diameter of a borehole; often referred to a "bit size".
Nom_Cable_Depth	Depth	Nominal cable depth, such as that planned for the receiver cable in a marine seismic survey.
Nom_Diameter	Diameter	Nominal (approximate, for naming purposes only) diameter of an object.
Nom_Flowrate	Flowrate	Nominal Flow Rate
Nom_Hydraulic_Power	Hydraulic_Power	Hydraulic (Flowrate x pressure) power that the equipment can sustain over a long period of time, as opposed to maximum working pressure which is the peak maximum
Nom_Inside_Diameter	Inside_Diameter	Nominal (approximate, for naming purposes only) inside diameter of an equipment item.
Nom_Length	Length	Nominal (approximate, for naming purposes only) length of an equipment item.
Nom_Liquid_Capacity	Volume	Volume of fluid which can be contained in the vessel
Nom_Max_Outside_Diameter	Max_Outside_Diameter	Nominal maximum outside diameter, such as for a pilot hole.
Nom_Near_Trace_Offset	Seismic_Offset	Nominal in-line offset between the sources and the first receiver group on each cable (for symmetric configurations)
Nom_Outside_Diameter	Outside_Diameter	Nominal (approximate, for naming purposes only) outside diameter of an equipment item.
Nom_Pressure_Loss	Pressure_Loss	The nominal pressure loss in a piece of equipment, such as a Drill_Motor or an MWD_Tool.
Nom_Receiver_Group_Distance	Length	Nominal distance between consecutive receiver groups
Nom_Source_Depth	Depth	Planned depth for the source
Nom_Station_Distance	Length	Nominal distance between stations on a seismic line
Nom_Station_Increment	Count	Nominal increment in station number for consecutive stations
Nom_Thickness	Thickness	Nominal thickness
Nom_Weight	Weight	Nominal (approximate, for naming purposes only) weight of an equipment item.
Nomenclature_Code	Code	Code built by compounding different codes e.g. drill fluid code built on product-packaging type: 103481052 means Barite API(103481) in 50kg sack (052).
Nominal	Modifier	Approximate, for naming purposes only. For example, the nominal lengths of drill pipe sections may be 30 feet, but the actual length of each section will vary.
Nominal_Receiver_Correction	Correction	Nominal correction vector to receiver position
Nominal_Receiver_Dx	X_Coordinate	X coordinate of nominal correction vector to receiver position.
Nominal_Receiver_Dy	Y_Coordinate	Y coordinate of nominal correction vector to receiver position.
Nominal_Receiver_Dz	Z_Coordinate	Z coordinate of nominal correction vector to receiver position.
Nominal_Source_Correction	Correction	Nominal correction vector to source position
Nominal_Source_Dx	X_Coordinate	X coordinate of nominal correction vector to source position.
Nominal_Source_Dy	Y_Coordinate	Y coordinate of nominal correction vector to source position.
Nominal_Source_Dz	Z_Coordinate	Z coordinate of nominal correction vector to source position.
Non_Darcy_Flow_Coefficient	Indicator	Non-Darcy (turbulence) flow coefficient ("D")
Non_Darcy_Skin	Skin_Factor	The skin effect resulting from turbulent flow conditions within the reservoir or the completion. This is the only skin which is flowrate dependent.
Non_Magnetic_Flag	Flag	A flag indicating whether the equipment is made with non magnetic material.
Non_Zero_Sample_Count	Count	Number of samples that do not have a value of zero.
None	Property	No property code applies; this is a temporary property type used to flag Parameters and Arrays for which we cannot make a meaningful mapping to any Property.
Normal_Moveout	Time_Interval	The additional time required for energy to travel from a source to a flat reflecting bed and back to a geophone at some distance from the source point compared to the time to return to a geophone at the source point.
Normalization_Factor	Coefficient	Coefficient used to normalize data for comparison or correlation.
Normalized	Modifier	The data related to the property has been corrected so that its range corresponds to a prescribed norm.
Normalized_Distance	Length	Normalized distance to the center of a point cluster in multi-dimensional attribute-space.
Normalized_Quantity	Statistical_Property	Normalized property derived by a statistical algorithm normalizing between 0. and 1. the original values of some numerical data; the original data Property code and normalization range may be documented in Remarks.
North_Departure	Y_Coordinate	Displacement to the North relative to some coordinate system origin; e.g., the north component of the well departure from the vertical. (Negative value is departure to the South.)
North_South_Distance	Y_Coordinate	North or South distance to the boundary line indicated by North_South_Line to the survey point.
North_South_Line	Type	Indicates whether the North or South boundary line of the survey area has been used as a reference for North_South_Distance values.
Northing_Latitude	Latitude	Latitude of Northing reference point.
Northing_Longitude	Longitude	Longitude of Northing reference point.
Nozzle_Count	Count	The number of nozzles in an equipment item, such as a drill bit.
Nozzle_Size	Diameter	Diameter of the nozzle(s) used in an equipment item, such as a drill bit
Nuclear_Magnetic_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a nuclear magnetism measurement.
Object_Identifier	Identifier	Identifier of the seismic object within the Foreign System
Object_Name	Name	Name of an Object
Observed	Modifier	Seen or sensed especially through directed careful analytic attention.
Occurrence	Description	Description of where an object, material or phenomenon may occur or be found.
Occurrence_Order	Type	The order of occurrence of a particular item.
Occurrence_Probability	Probability	The probability that an item (element, mineral, ..) occur within a particular environment under certain conditions.
Offset	Multi_Use_Property	Difference from a reference value, generally zero.
Offshore_Block_Number	Identifier	Identification of the Offshore block where the well is located
Oil_Acoustic_Velocity	Acoustic_Velocity	Sound velocity of live oil at reservoir pressure and temperature. Typical value is 1000 m/s.
Oil_Brine_Ratio	Volume_Fraction	Ratio of oil volume to brine volume for a fluid, such as an oil based mud
Oil_Bubble_Flow_Velocity	Flow_Velocity	Oil Bubble Velocity
Oil_Compressibility	Compressibility	The compressibility of oil at a given pressure and temperature.
Oil_Compressibility_Correlation	Name	Name of the correlation model (often the author name) used to compute oil compressibility (e.g. Calhoun, Vasquez and Beggs)
Oil_Concentration	Volume_Fraction	Oil Concentration per fluid Volume
Oil_Connection_Size	Diameter	Standard oil pipe size connection supplied on the equipment inlet
Oil_Density	Density	The density of oil.
Oil_Flow_Velocity	Flow_Velocity	Flow velocity of oil component of fluid.
Oil_Flowrate	Flowrate	Rate of flow of oil
Oil_Formation_Volume_Factor	Formation_Volume_Factor	For a sample of oil and its residual solution gas at surface, the ratio of the volume at specified (typically, reservoir) conditions to the volume at surface (stock tank) conditions. Normally abbreviated Bo; typical range 1.1 - 2.
Oil_Formation_Volume_Factor_Correlation	Name	Name of the correlation model (often the author name) used to compute oil formation volume factor (Vasquez_Beggs, Glaso, Standing)
Oil_Fraction	Volume_Fraction	Volumetric fraction of oil in the total fluid
Oil_Gravimeter_Type	Type	Type of instrument used to measure oil specific gravity
Oil_Gravity	Specific_Gravity	The ratio of the density of the produced or reservoir oil to that of pure water at atmospheric conditions. See also API_Gravity
Oil_Holdup	Holdup	Volume fraction of oil in the upward-moving stream of a producing well.
Oil_Line_Temperature_Gauge_Type	Type	Type of gauge used to measure oil line temperature of separator
Oil_Mass_Flowrate	Mass_Flowrate	Mass flowrate of oil.
Oil_Metering_Line_Size	Diameter	Diameter of the oil metering line
Oil_Probability	Probability	The probability that oil is present in the formation.
Oil_Rate_Meter_Type	Type	Type of liquid meter used to measure oil rate
Oil_Sampling_Point	Location	The location where oil samples are taken on the separator
Oil_Saturation	Saturation	The extent to which the pore space in a formation contains oil.
Oil_Temperature	Fluid_Temperature	The temperature of oil under certain conditions.
Oil_Viscosity	Viscosity	The viscosity of oil at specific temperature and pressure conditions.
Oil_Viscosity_Correlation	Type	Model used to compute oil viscosity
Oil_Volume_Fraction	Volume_Fraction	The volume fraction of oil with respect to the total volume; the product of Porosity and Oil_Saturation
Oil_Water_Contact_Depth	Depth	The depth at which oil water contact has been recognized in a Reservoir Unit.
Oil_Water_Ratio	Volume_Fraction	Ratio of oil volume to water volume for a fluid, such as an oil based mud
Oil_Wettability_Index	Wettability_Index	Relative affinity of a mineral surface for oil. Amott
One_Hour_Pressure	Pressure	Pressure measured 1 hour after start of test.
One_Way_Time	Acoustic_Travel_Time	The time required for an acoustic wave to travel directly from one point to another; used to distinguish from Two_Way_Time.
Open_Fraction	Ratio	Fraction to which the equipment is open, e.g., 50% open
Operating_Mode	Type	Operating mode of an equipment
Operating_System_Name	Name	Name of computer Operating System, e.g. Unix, VMS, Windows NT.
Operating_System_Version	Version	Version of computer Operating System
Operating_Time	Time_Interval	Period of time which is spent operating, either for a single operation or for a series of operations. Complement of Idle_Time.
Operator	Organization_Code	The code of an operator, usually that of a Service, Contractor, Vendor or E&P company
Operator_Name	Organization_Name	The name of an operator of a well, an equipment, etc.
Optimum_Flag	Flag	Indicates whether the activity, process or solution is optimum.
Optional_Blade_Height	Blade_Height	Optional height of blade at gauge from the body of the equipment, such as a stabilizer (extended Andergauge); used as a supplement to Blade_Height.
Ordered_Flag	Flag	Flag to indicate whether the members of a set have been ordered.
Ordinal_Number	Data_Valued_Property	A number used to indicate the position, rank or order of items in a sequence.
Organization_Code	Code	Catalog-controlled code of Organization.
Organization_Name	Name	Name of organization
Organization_Role	Type	Role of organization (e.g. Business Associate)
Orientation	Data_Valued_Property	The spatial orientation of an object. Usually defined by a vector who origin location is known relative to a coordinate system (e.g., in spherical coordinates, the Vector will be defined by the 3 angles Rho, Theta and Phi)
Orifice_Meter_Gas_Temperature	Temperature	Temperature of gas at orifice meter line when a sample is taken
Orifice_Plate_Diameter	Diameter	Diameter of orifice plate in gas metering system when a sample is taken
Origin_Easting	X_Coordinate	The easting of the point of origin of an orthogonal grid constructed on a map projection. Often, this value is defined to be a positive number to avoid negative coordinates. Sometimes called "false easting".
Origin_Latitude	Latitude	The latitude of the point of origin of an orthogonal grid constructed on a map projection. Frequently this is a projection standard parallel, but can be any defined latitude.
Origin_Longitude	Longitude	The longitude of the point of origin of an orthogonal grid constructed on a map projection. Frequently this is the central meridian, but can be any defined longitude
Origin_Northing	Y_Coordinate	The northing of the point of origin of an orthogonal grid constructed on a map projection. Often, this value is defined to be a positive number to avoid negative coordinates. Sometimes called "false northing".
Origin_Rho	Radius	Radial distance of the origin of a Local Coordinate System, measured with respect to the origin of the "from" coordinate system. Units, if any, are those of the "from" system.
Origin_X	X_Coordinate	X component of the location of the origin of a Local Coordinate System, measured with respect to the origin of the "from" coordinate system. Units, if any, are those of the "from" system.
Origin_Y	Y_Coordinate	Y component of the location of the origin of a Local Coordinate System, measured with respect to the origin of the "from" coordinate system. Units, if any, are those of the "from" system.
Origin_Z	Z_Coordinate	Z component of the location of the origin of a Local Coordinate System, measured with respect to the origin of the "from" coordinate system. Units, if any, are those of the "from" system.
Original_Expiry_Date	Expiry_Date	The original date that the contract was to terminate. If the contract is extended, this date does not change.
Orthoclase_Volume_Fraction	Volume_Fraction	The volume fraction of orthoclase with respect to the total volume.
Outer_Boundary_Condition_Type	Type	Description of the outer boundary condition for a well test model.
Outer_Continental_Shelf_Name	Name	Name of the submerged land area called the Outer Continental Shelf
Outer_Pipe_Inside_Diameter	Inside_Diameter	Inside diameter of a pipe in external position within an annulus
Outlet_Connection_Size	Diameter	The connection size of the output line to the equipment
Output_Pressure	Pressure	Pressure at the output of an equipment item.
Outside_Diameter	Diameter	Outside diameter of an entity, such as an item of drillstring equipment
Ovality	Shape	Degree of departure from roundness. Often measured as the ratio of large diameter over small diameter of an ellipse or an ellipsoid body
Overbalance_Pressure	Pressure	The difference between formation pressure and the pressure of the fluid in the borehole.
Overburden_Pressure	Pressure	The pressure exerted on the matrix of a porous media by the weight of overlying strata.
Owner_Name	Organization_Name	The name of the owner of an item like a piece of equipment.
Ownership_Amount	Proportion	Lessor percentage ownership
Oxygen_Yield	Elemental_Yield	Elemental contribution of Oxygen with respect to total.
PI_Code	Identifier	Petroleum Information Alpha-Numeric code
PI_Code_Series	Identifier	Petroleum Information Alpha-Numeric code series. Example 110 for Producing Wells, 400 for Gas Injection Wells.
P_Wave_Angle	Plane_Angle	P-wave angle
Package_Size	Amount	Quantity of material contained in each package. Unit depends upon the type of material and packaging.
Packaging_Code	Code	Identifier of the packaging e.g. 303: 50 gal Drum
Packaging_Type	Type	Type of Packaging or container used for products, such as Drum, Sack, Bulk, Pieces, Pallets
Packaging_Unit	Code	Code of a packaging unit
Packer_Depth	Depth	Depth at which the packer is set.
Packer_Inside_Diameter	Inside_Diameter	Packer internal diameter (Casing_Tubing Packer)
Packer_Motion_Type	Type	Internal tubular (e.g. tubing) motion allowed by the packer during an increase in pressure. Choices: Free (Packer does not restrain motion), Limited (tubular is free to shorten but not lengthen) and No Motion.
Packer_Type	Type	Type of packer; supplier type like Dowell Model 21. No simple type description available but the supplier identification.
Pad_Force	Force	Tool pad force
Pad_Pressure	Pressure	The pressure with which the pad of a logging or testing device is applied to the formation or other interface.
Parallel_Porosity_Volume_Fraction	Volume_Fraction	The volume fraction of parallel porosity with respect to the total volume.
Parameter_Label	Annotation	String carrying the short explanation of a parameter, for use in user interface
Parent_Code	Code	Code of the supertype or parent of this object type.
Part_Number	Identifier	Identifier used for accounting or purchasing purpose to identify an equipment item.
Partial_Completion_Model	Type	Model used to compute the Partial Completion apparent skin effect
Partial_Completion_Skin	Skin_Factor	The skin effect caused by flow convergence due to not completing the entire flowing thickness. Does not include the skin due to the completion itself.
Particle_Displacement	Displacement	The distance a particle is moved from its equilibrium position, as in ground motion associated with a seismic wave.
Pass_Through_Diameter	Inside_Diameter	Equipment (e.g. drillbit) attribute which specifies the minimum inside diameter of casing through which the equipment will pass.
Pattern_Length	Interval_Length	The length of a pattern, usually pertaining to a dip pattern or a geological feature. The length is usually an interval length like depth.
Pattern_Name	Name	Name of a pattern or style, such as a graphic pattern.
Peak_Peak_Amplitude_Ratio	Ratio	Ratio of amplitudes of two peaks.
Peak_Peak_Delta_Amplitude	Amplitude	Amplitude difference between two peaks.
Peak_Peak_Delta_Depth	Thickness	Depth difference between successive peaks
Peak_Peak_Delta_Time	Time_Interval	Time difference between two peaks.
Peak_Trough_Amplitude_Ratio	Ratio	Ratio of amplitudes of peak and trough.
Peak_Trough_Delta_Amplitude	Amplitude	Amplitude difference between peak and trough.
Peak_Trough_Delta_Depth	Thickness	Depth difference between peak and trough where peak occurs first in increasing depth
Peak_Trough_Delta_Time	Time_Interval	Time difference between peak and trough.
Penetration_Depth	Depth	Depth to which some medium is penetrated, such as by a drill bit or probe, or by fluid invasion. (Not to be used for borehole depth.)
Penetration_Rate	Velocity	Usually used to describe the rate at which a formation is penetrated during drilling operation. In general, the rate at which an equipment penetrates a surface or subsurface volume.
Perforation_Charge_Type	Type	Type of explosive charge used in a perforating gun.
Perforation_Count	Count	Total number of perforations over the perforated interval
Perforation_Diameter	Diameter	The diameter of the perforation entrance hole. Often called Entrance Hole Diameter.
Perforation_Distance	Interval_Length	Distance from the top of the hydraulic unit to the top of the perforations. For use in the partial penetration model.
Perforation_Gun_Phase	Type	Phasing of the perforating gun for the given perforated interval. Standard phasings include Inline (0 deg), Spiral (45, 60, 90, 120, 180 deg), Tangential(90-270 deg).
Perforation_Gun_Position	Type	The position of the perforating gun relative to the tubing/casing in the borehole. Options include: Positioned (usu. Through-Tubing guns), Not Positioned (usu. Casing guns), Centralized.
Perforation_Gun_Standoff	Standoff	Standoff of Perforation Gun
Perforation_Gun_Type	Type	The type of perforating gun used to shoot the given interval of the tubing (or casing) in the borehole. Examples are: 3-3/8" 6 SPF, 3-3/8" HJ HI-TEMP, 4" HJ II, etc.
Perforation_Length	Length	Length of the portion of the perforation which extends from the casing beyond the cement sheath and into the reservoir. It includes the casing thickness and the cement sheath thickness.
Perforation_Pressure_Condition	Flag	Pressure condition in the well at the time of perforating; may be Underbalanced (pressure in formation higher than in borehole) or Overbalanced (pressure in borehole higher than in formation.
Perforation_Shot_Density	Data_Valued_Property	The perforation density; i.e., the number of shots per unit length.
Perforation_Status	Status	Not perforated, perforated, plugged or squeezed
Perforation_Type	Type	The method used to open the production in the borehole. Examples are: Bullet, Jet, Combination, Open Hole, etc.
Period	Time_Interval	The time T for one cycle of a periodic function. The time for a wave crest to traverse a distance equal to one wavelength. The reciprocal of Frequency.
Permeability	Data_Valued_Property	A property of rock (formation) denoting its ability to pass fluids through its interconnected pores.
Permeability_Axial_Path	Directional_Permeability	Permeability measured along the length of a core cylinder.
Permeability_Thickness	Volume	The product of permeability and thickness of the body acting as a conduit.
Permeability_Thickness_Ratio	Ratio	Ratio of component permeability-thickness to total system permeability-thickness [kh(i) / kh(total)], usually known as Kappa in reservoir dynamics work.
Permeability_Transverse_Path	Directional_Permeability	Permeability measured in the plane transverse to the length of the core cylinder. This may be represented as a single measurement in the flow plane or as a two component permeability represented as a measurement along an arbitrary diameter and another along an orthogonal path in the same plane.
Permittivity	Data_Valued_Property	The property of a material that enables it to store electrical charge, typically measured in farad/m. Free space has a Permittivity of 8.854E-12 farad/m.
Person_Name	Name	Name of a person
Personnel_Count	Count	Headcount of personnel satisfying role of Personnel_Role; these may be implemented as lists.
Personnel_On_Board	Count	Count of number of people on board the vessel or structure.
Personnel_Role	Type	Role of the personnel counted in Personnel_Count; these may be implemented as lists.
Perspective_Height	Height	Height of the point of perspective; used in general perspective map projections.
Pf_Titration_Volume	Volume	Amount of 0.02 normal (N/50) standard sulfuric acid required in order to turn the color of phenolphthalein indicator solution from pink to colorless when determining phenolphthalein alkalinity of the mud filtrate, Pf, API RP13 Section 8, Chemical Analysis.
Phase_At_Envelope_Maximum	Instantaneous_Phase	Instantaneous phase at maximum of reflection strength. Similar to Response_Phase, but with maximum within a user-defined interval.
Phase_Shift	Plane_Angle	The result of adding or subtracting from a phase measurement.
Phase_Shift_Resistivity	Electromagnetic_Propagation_Resistivity	Formation resistivity as measured by the phase shift of a high frequency electromagnetic wave (hundreds of KHz to several MHz, 1.1 GHz in the case of Schlumberger's EPT tool); these measurements are typically sharp (good vertical resolution) and have good dynamic range, but their depth of investigation is less than that of measurements based on attenuation.
Phase_Velocity	Acoustic_Velocity	The velocity of any given phase (such as a trough) or a wave of single frequency; may differ from Group Velocity due to dispersion in the medium.
Phone_Number	Address	Telephone number
Phosphorus_Yield	Elemental_Yield	Elemental contribution of Phosphorus with respect to total.
Photoelectric_Factor	Data_Valued_Property	A measure of the probability that scattering due the Photoelectric Effect will occur; often expressed in an approximation unit barns/electron.
Photoelectric_Factor_Quality_Indicator	Quality_Indicator	Property used to indicate quality or confidence of data from a photoelectric factor survey.
Pick_Quality	Quality_Indicator	Pick quality measurement.
Pickup_Friction_Coefficient	Coulomb_Friction_Coefficient	Friction coefficient between a string and the borehole when pulling out of the hole
Pickup_Hook_Load	Hook_Load	Driller estimate of the average pickup hook load (pickup weight) over the reporting period.
Pickup_Reel_Back_Tension	Tension	Amount of tension kept on the coiled tubing between the gooseneck and the reel when pulling out of the hole
Pipe_Inside_Diameter	Inside_Diameter	Inside diameter of pipe
Pipe_Outside_Diameter	Outside_Diameter	Outside diameter of pipe
Pitch_Length	Length	Measure of slope using the linear distance between two successive points: on a screw, between threads, measured parallel to the axis; for a propeller or spinner, the theoretical axial displacement corresponding to one revolution.
Plane_Angle	Data_Valued_Property	The angular displacement between two lines extending from the same point, measured in the plane of the two lines.
Plane_Angle_Unit	Unit_Code	Unit for Plane Angle data
Plane_Type	Type	The type of a plane in the Earth subsurface, e.g. Bed Plane, Fault Plane, Fracture Plane, etc.
Planned_Depth	Measured_Depth	The planned measured depth at the end of the reporting period, as described on the driller depth log of the planned borehole
Plastic_Viscosity	Viscosity	Apparent viscosity of the Bingham Plastic model : Slope of the curve shear stress vs. shear rate (rheogram). Model equation is Shear_Stress = Yield_Stress + Plastic_Viscosity times Shear_Rate.
Platform_Type	Type	The type of a platform.
Play_Type	Type	A type or code assigned to a lease. Play codes can be internal to company and are usually based upon geographic boundaries or geologic trends.
Plug_Back_Total_Depth	Depth	Measured Depth of the current bottom of the borehole. It is the physical bottom of the borehole which is plugged either by a cement or by a mechanical plug. The P.B.T.D. can changes in time. It is smaller than the total depth drilled.
Plunger_Count	Count	Number of plungers e.g. 3 for a triplex pump.
Plus_Tolerance	Tolerance	Amount of positive tolerance on a measurement value; the unit quantity is determined by that of data value.
Pm_Titration_Volume	Volume	Amount of 0.02 normal (N/50) standard sulfuric acid required in order to turn the color of phenolphthalein indicator solution from pink to colorless when determining phenolphthalein alkalinity of the mud, Pm, API RP13 Section 8, Chemical Analysis.
Point_Type	Type	The type of an Earth zero-dimensional object such as a marker.
Poisson_Ratio	Ratio	Ratio of the transverse contraction of a body to its longitudinal extension when stretched. Typical values in minerals are from 0.15 to 0.3 (Carbonates:0.15, Sandstones:0.2, Shales:0.25).
Polarity_Ratio	Ratio	Ratio of number of positive samples to total number of samples. Equivalent to Threshold_Ratio where threshold is zero.
Polarity_Reversal_Flag	Flag	When set, apply reverse polarity.
Polarization_Azimuth	Azimuth	Shear energy polarization azimuth angle measured clockwise from grid north.
Polynomial_Order	Ordinal_Number	Order of term in a polynomial, such as in a multiple regression equation.
Polyol_Concentration	Chemical_Concentration	Polyol Concentration per fluid Volume (Polyol are glycol-glycerol alcohol derivatives)
Pond_Depth	Depth	For a centrifuge, Position of overflow Port relative to Inner Bowl Wall
Population	Count	A count of the number of persons or objects.
Pore_Pressure	Pressure	The pressure of the fluid contained in the pore volume.
Pore_Pressure_Gradient	Pressure_Gradient	The change in pore pressure per unit length.
Pore_Pressure_Safety_Factor	Safety_Factor	Amount by which borehole pressure should normally exceed pore pressure, to allow for uncertainty in pore pressure estimation.
Pore_Throat_Diameter	Diameter	The measured or effective diameter of the aperture which connects pores or void spaces within a rock matrix.
Pore_Volume	Volume	The volume within a geologic volume that describes the connected void space within the matrix of rock.
Pore_Volume_Compressibility	Compressibility	The relative change in the pore volume of a rock under conditions of changing confining pressure.
Porosity	Volume_Fraction	Pore volume per unit gross volume. Porosity is determined from measurements on cores or interpreted from logs.
Porosity_Correction	Correction	Correction to a Porosity measurement.
Porosity_Length_Ratio	Ratio	The ratio of the sum of layer porosity thicknesses to total system porosity thicknesses for a layered porous media.
Porosity_Type	Type	The porosity type usually of a core sample or in either a carbonate or clastic rock formation (e.g. Intercrystal, Breccia, Vuggy, etc.),
Port_Count	Count	Number of ports, such as in a Coiled Tubing BHA
Port_Diameter	Diameter	Diameter of each individual port
Positive	Modifier	Real and numerically greater than zero.
Positive_Slope	Multi_Use_Property	Positive slope value.
Positive_Threshold	Threshold	Positive threshold value.
Post_Cursor_Amplitude	Amplitude	Difference in seismic amplitude between a reference position and the corresponding deeper extreme.
Postal_Address	Address	Location to which postal correspondence may be sent for a person, business or other entity.
Potash_Volume_Fraction	Volume_Fraction	The volume fraction of potash with respect to the total volume.
Potassium_Concentration	Concentration	Concentration of Potassium by weight.
Potassium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of potassium to total dry weight
Potassium_Ion_Concentration	Chemical_Concentration	Potassium K+ cation concentration
Potassium_Yield	Elemental_Yield	Elemental contribution of Potassium with respect to total.
Power	Data_Valued_Property	The time rate at which work is done or energy emitted or transferred.
Power_Supply_Start_Time	Start_Time	Actual date and time at which the recorder was powered on.
Pre_Cursor_Amplitude	Amplitude	Difference in seismic amplitude between a reference position and the corresponding shallower extreme.
Precision	Statistical_Property	The repeatability of an instrument measured by the mean deviation of a set of measurements from the average value; the unit quantity is determined by that of the data.
Preferred_Flag	Flag	An indicator which shows that a particular item is preferred over another, normally as a result of some interpretation or validation process.
Preparation_Method	Method_Type	Method by which an item or sample has been prepared for subsequent operations or analysis.
Prescale_Offset	Multi_Use_Property	Special Offset value used in certain calibrations It is not part of the Calibration_Coefficient list.
Preservation_Method	Method_Type	Method by which an item or sample, such as a core sample, has been preserved.
Pressure	Data_Valued_Property	The force or thrust exerted over a surface divided by its area; e.g., hydrostatic, flow, pump, etc. May be gauge or absolute.
Pressure_Accuracy	Accuracy	The maximum difference, over the calibrated range, between pressure applied to the gauge, with a reference standard, and the pressure measured by the gauge.
Pressure_Digit	Pressure	Element of a representation for pressure data in which each digit in the decimal pressure (1's, 10's, 100's, etc. )is stored as a separate unitless digit. This method is obsolete, but the property is needed for mapping historical data.
Pressure_Drop_Correlation	Type	Pressure drop correlation (e.g., Dun-Ros, Cullender, )
Pressure_Drop_Correlation_Type	Type	Pressure drop correlation (e.g., Dun-Ros, Cullender, etc. )
Pressure_Gradient	Gradient	The change in pressure per unit length.
Pressure_Loss	Pressure	The difference between input and output pressure, usually due to friction.
Pressure_Measure_Point	Measure_Point_Offset	The distance from the bottom of the Equipment to the point where the pressure is measured.
Pressure_Operation_Type	Type	Type of pressure-operated mechanism. Certain tools are be operated by either tubing or annulus pressure. These tools frequently contain a rupture disk or break plug and are single-shot.
Pressure_Point_Setup	Type	Identifies the location of the fluid whose pressure is being recorded.
Pressure_Point_Setup_Code	Code	Encoding of the pressure point position setup of a Testing Tool by concatenation of the PRESSURE_POINT_SETUP enumeration separated by space, e.g., "Tubing-Above-Valve Annulus Empty"
Pressure_Rate	Data_Valued_Property	A measure of the rate at which pressure varies per time; e.g., slider pressure correction.
Pressure_Sensor_Code	Code	Pressure sensor code
Pressure_Sensor_Drift	Pressure	Pressure difference over time in the gauge output with constant input conditions
Pressure_Sensor_Noise	Noise_Amplitude	Random changes in pressure sensor response.
Pressure_Sensor_Resolution	Pressure	The minimum significant pressure change that can be detected above the noise. This is measured as the standard deviation of the differences between two successive measurements.
Pressure_Sensor_Type	Sensor_Type	Pressure sensor type
Pressure_Unit	Unit_Code	Unit for Pressure data
Primary_Output_Flag	Flag	Flag indicating that data constitute a valid primary output (1) or an auxiliary output (0)
Primary_Porosity	Porosity	The porosity remaining after sediments have been deposited but without considering changes because of subsequent chemical action or water flow.
Prime_Meridian_Greenwich_Offset	Longitude	Longitude of the prime meridian referenced from the meridian through Greenwich. Positive denotes east of Greenwich. Example: PARIS PANTHEON meridian in France is at longitude 2.337229 degrees.
Prime_Meridian_Name	Name	Name of the meridian from which longitudes are referenced. Normally the meridian through Greenwich is defined as the prime meridian.
Principal_Meridian	Longitude	Principal Meridian of Jeffersonian_Parcel
Priority	Data_Valued_Property	Superiority in rank, position, or privilege
Probability	Data_Valued_Property	The likelihood that a given event will occur, expressed as the ratio of the number of occurrences of the specified event to the total number of events.
Processing_Option	Indicator	An indicator of which of two or more options has been selected for data processing.
Processing_Window_Length	Interval_Length	Length of processing window
Processing_Window_Length_Depth	Interval_Length	Length of processing window in depth domain
Processing_Window_Length_Time	Time_Interval	Length of window in time domain
Produced_Fluid_Compressibility	Compressibility	Compressibility of the Total Produced Fluid for the Hydraulic Unit. It is corrected from Reservoir_Fluid_Compressibility by taking into account the actual volume fractions produced based on the saturation of the fluid within the reservoir.
Producing_Gas_Liquid_Ratio	Gas_Liquid_Ratio	The ratio of produced gas to produced liquid (oil + water) at the wellhead
Producing_Thickness	Thickness	Total flowing thickness along the Borehole ("Hp")
Producing_Water_Cut	Water_Cut	Producing Water Cut from the Hydraulic Unit
Product_Code	Code	The code of a chemical product sometimes named alphacode e.g. D013
Product_Name	Name	Official product name.
Production_History_Flag	Flag	Flag indicating whether or not this Flow Period is part of the Production History; i.e., set for Production History, not set for Test History
Production_History_Reference_Time	Reference_Time	Reference Date and Time for Production History
Production_History_Type	Type	Type of production/Injection data set : Previous_Flow_History (Production), Injection, Previous_Flow_History (Production), Simulated_Behavior (Test), Actual_Field (Flow)
Productive_Flag	Flag	Indicates whether object or activity is productive. An activity is considered productive if it brings the operation closer to achieving the objective.
Productivity_Index	Mobility	Ratio of flow rate to pressure drop. For oil wells, PI is normally expressed in barrels per day per psi decline in bottomhole flowing pressure.
Productivity_Ratio	Ratio	Productivity ratio (actual productivity index divided by ideal (zero skin) productivity index)
Profile_Conductance	Conductance	Measurement related to conductance but not necessarily scaled or calibrated for quantitative use.
Profile_Conductivity	Conductivity	Conductivity profile measurement, used primarily for pattern recognition; may or may not be calibrated.
Profile_Resistivity	Resistivity	Resistivity profile measurement, used primarily for pattern recognition; may or may not be calibrated.
Projection_Azimuth	Azimuth	Azimuth of positive y-axis of projection.
Projection_CS_Type	Type	The type of a Projection coordinate system, e.g. Lambert, UTM, State Plane, etc.
Projection_Class	Type	Base projection type (e.g. TM for UTM_1)
Projection_Code	Code	Catalog code of a Projection coordinate system.
Projection_Name	Name	Name of the projection coordinate system.
Projection_Point_Mode	Flag	Flag determining number of points used in defining certain projections, 0,1,2
Projection_Quadrant	Flag	Quadrant in which X and Y axes are positive, 1,2,3, or 4
Projection_Relative_Bearing	Azimuth	Projection relative bearing
Projection_Scale_Factor	Scale_Factor	Scale Factor which is used as a defining parameter for a projection, typically taken along the Central Meridian or along one of the major parallels
Projection_Scale_Reduction	Scale_Factor	A number by which the scale along a designated meridian, great circle, or parallel is reduced or enlarged during the projection process to reduce the scale error elsewhere in the projection.
Projection_Zone_Code	Name	UTM Zone of projection.
Property		Any SDM Property defined in this catalog
Property_Code	Code	Catalog code of SDM Property
Proportion	Ratio	The ratio of one part of an amount to the whole, with respect to quantity or magnitude.
Proposal_Number	Identifier	Customer proposal number
Proppant_Areal_Distribution	Concentration	Mass of proppant per fracture area (hydraulic fracturing)
Proppant_Concentration	Concentration	Proppant concentration expressed as mass of proppant added per gallon of gel, legacy (LIS) unit "PPA"
Proppant_Density	Density	The density of the proppant material
Proppant_Permeability_Factor	Ratio	Fraction of proppant permeability retained in the in-situ fracture condition, and due to mechanical damage excluding any damage due to fluid residue. Has the same effect than Fluid_Permeability_Factor.
Propped_Bottom_Depth	Depth	Bottom Depth of proppant laden slurry volume during the propagation of an hydraulic fracture considered along the well bore..
Propped_Half_Length	Length	Half Length of the part of an hydraulic fracture which is filled by proppant laden slurry . It is shorter during fracture propagation than the fracture half_length as the propped slurry follows a gel volume w/o proppant , the "clean" fluid
Propped_Top_Depth	Depth	Top Depth of proppant laden slurry during the propagation of an hydraulic fracture considered along the well bore. Often named Slurry height. At fracture closure, Propped_Top_Depth = Fracture_Height.
Propped_Width	Width	Width of the proppant laden volume within an hydraulic fracture (hydraulic fracturing). Smaller during fracture propagation than the fracture width.
Pseudo	Modifier	Spurious.
Pseudocritical_Pressure	Critical_Pressure	The pressure needed to condense the vapor of a gas mixture at its pseudocritical temperature. Analogous to Critical_Pressure for pure components.
Pseudocritical_Temperature	Critical_Temperature	The highest temperature at which a fluid can exist as a liquid and above which its vapor cannot be liquefied regardless of the amount of pressure. Used for mixtures, analogous to Critical_Temperature for pure components.
Publication_Date	Date	Date of publication of a document.
Publication_Title	Title	Title of publication of a document.
Publisher_Name	Organization_Name	Name of Organization which published of a document.
Pump_Liner_Diameter	Diameter	Diameter of the pump entry line
Pumping_Schedule_Type	Type	Type of pumping schedule i.e. as measured, design, alternate...
Pumping_Time	Operating_Time	Elapsed time during which pumping has taken place.
Purchase_Number	Identifier	Purchase Order Number
Put_Function_Name	Function_Name	Name of function used to write data.
Pyrite_Volume_Fraction	Volume_Fraction	The volume fraction of pyrite with respect to the total volume.
QHSE_Report_Count	Count	Number of QHSE reports issued for the reporting period
Q_Ratio	Ratio	Quality factor for compressional waves. The ratio of 2*pi times the peak compressional wave energy to the energy dissipated in a cycle.
Qs_Ratio	Ratio	Quality factor for shear waves. The ratio of 2*pi times the peak shear wave energy to the energy dissipated in a cycle.
Quality_Factor	Data_Valued_Property	Factor which quantitatively characterizes the acoustic attenuation of a medium.
Quality_Indicator	Indicator	Property which provides a relative measure of the quality or fitness-for-purpose of data, or of some item, process, or material.
Quartz_Volume_Fraction	Volume_Fraction	The volume fraction of quartz with respect to the total volume.
RMS_Amplitude	Amplitude	Root Mean Square of amplitudes.
RMS_Velocity	Acoustic_Velocity	Transit-time weighted root mean square of the interval velocities over a series if intervals.
RP66_Array_Code	Array_Code	Code or Identifier of this type of RP66 Channel object.
RP66_Index_Code	Code	Code or Identifier of an RP66 axis index measured or computed by some activity, e.g. MD, TVD, etc.
RP66_Parameter_Code	Code	Code or Identifier of this type of RP66 Parameter object.
Radial_Length	Length	Length measured in a radial direction.
Radioactivity	Data_Valued_Property	The measure of intensity of radiation from a material relative to a standard level of intensity.
Radius	Length	Radius of an entity with a spherical or cylindrical shape, such as the borehole, an item of drillstring equipment, etc.
Ramping_Duration	Time_Interval	Time duration of the ramp tapering the time window
Ramping_Method	Method_Type	Method to ramp (tapering) the time window, e.g., Hamming, Hanning...
Range_Number	Identifier	Jeffersonian Range Number
Range_Type	Type	Specification whether the value range is inclusive[], exclusive (), or mixed: [) or (].
Rank	Ordinal_Number	Integer denoting the order of an element in a collection, such as the rank of a Layer participating in a Sequence or Stratigraphic Column.
Rat_Hole_Bottom_Depth	Bottom_Depth	Bottom depth of the section of the borehole running from the tester valve to the effective bottom of the well
Rat_Hole_Diameter	Inside_Diameter	Diameter of the section of the borehole running from the tester valve to the effective bottom of the well
Rat_Hole_Volume	Volume	Available volume of fluids below testing valve. The rat hole is the section of the borehole running from the tester valve to the effective bottom of the well. The calculation of this volume is not straight-forward as the rat hole is not generally empty.
Ratio	Data_Valued_Property	The value of one item divided by the value of another item.
Raw	Modifier	Data which are uncalibrated and/or uncorrected; such data should be interpreted with caution.
Raw_Relative_Bearing	Azimuth	Raw relative bearing
Ray_Velocity	Group_Velocity	The velocity in the direction of energy transport; in anisotropic media it is different from the direction in which the phase velocity is measured. Also called group velocity.
Rayleigh_Slowness	Acoustic_Slowness	The acoustic slowness of a Rayleigh wave (type of seismic wave propagated along the free surface of a semi-infinite medium).
Rayleigh_Velocity	Acoustic_Velocity	The velocity of a Rayleigh wave (type of seismic wave propagated along the free surface of a semi-infinite medium.
Reactance	Impedance	The opposition to alternating current flow offered by inductance or capacitance; the quadrature component of impedance.
Read_Only_Flag	Flag	Flag indicating that a record is available for read access only (cannot be updated or deleted).
Receiver_Event_First_Arrival	Time_Interval	Time of arrival of first break for each receiver event
Receiver_Group_Count	Count	Total number of receiver groups attached to the cable
Receiver_Line_Position	Cylindrical_Position	Position in a receiver line
Receiver_Line_Rho	Radius	Horizontal (x-y) distance from origin of position in a receiver line.
Receiver_Line_Theta	Theta_Angle	Horizontal angle of position in a receiver line, measured counter-clockwise from x-axis.
Receiver_Line_Z	Z_Coordinate	Z-coordinate of position in a receiver line.
Receiver_Offset	Seismic_Offset	The distance to a seismic receiver from some other object, such as a wellbore in VSP work.
Receiver_Orientation	Spherical_Position	Downhole receiver orientation vector
Receiver_Orientation_Phi	Inclination	Vertical angle of downhole receiver, measured from the x-y plane.
Receiver_Orientation_Rho	Radius	Horizontal (x-y) distance from origin of downhole receiver.
Receiver_Orientation_Theta	Theta_Angle	Horizontal angle of downhole receiver, measured counter-clockwise from x-axis.
Receiver_Station_Datum_Elevation	Elevation	Datum elevation at each station relative to sea level
Receiver_Station_Time	Time_Interval	Time of first measurement for each station since the Origin_Time stored in Seis_Survey_Area
Reconstructed	Modifier	Rebuilt from other criteria.
Record_Length	Byte_Count	Total record length in bytes, such as for a seismic trace header.
Recorded	Modifier	Permanently registered.
Recorder_Code	Code	Code for the recorder
Recorder_Delay_Time	Time_Interval	Delay time between instrument power-on time and when recording begins
Recorder_Scanning_Rate	Data_Valued_Property	Scanning rate at which gauge records data
Recorder_Type	Type	Recorder type
Recovery_Factor	Volume_Fraction	Recovery factor of reservoir fluids expressed as the ratio of standard volumes (stock tank barrels, etc.) recovered to pore volume.
Recovery_Ratio	Ratio	Ratio of amount of sample or material recovered to total amount recoverable.
Rectangle_Length	Reservoir_Distance	The length distance between two parallel boundaries in a rectangular reservoir model.
Rectangle_Width	Reservoir_Distance	The width distance between two parallel boundaries in a rectangular reservoir model.
Rectangular_Position	Location	Set of coordinates specifying the position of a point in a rectangular coordinate system
Reduced_Pressure	Ratio	The pressure of a fluid divided by the critical pressure of the fluid.
Reduced_Temperature	Ratio	The temperature of a fluid divided by the critical temperature of the fluid.
Reduced_Traveltime	Time_Interval	Difference between observed refraction traveltime and the traveltime which would have been observed if only one head-wave velocity had been involved.
Reduced_Volume	Volume_Fraction	The volume of a fluid divided by the critical volume of the fluid.
Reel_Core_Diameter	Diameter	Drum core diameter, such as for a coiled tubing reel
Reel_Core_Width	Width	Width between flanges of the drum core, such as for a coiled tubing reel
Reel_Inlet_Pressure	Pressure	Pressure at the inlet of a coiled tubing reel.
Reference_Depth	Depth	Depth value used as a reference for other data
Reference_Location	Location	Location used as a reference for other data.
Reference_Pressure	Pressure	Reference Pressure, as for a PVT computation
Reference_Sack_Mass	Mass	Sack "weight" (mass) to which unit by sack refers e.g. lbs/sack
Reference_Time	Absolute_Time	Reference Date and Time For Elapsed Time
Reflection_Angle	Plane_Angle	The angle which the raypath of a reflected ray makes with the perpendicular to the interface. At the "reflection point" it is equal to the Incident_Angle for pressure-pressure or shear-shear reflections.
Reflection_Coefficient	Ratio	Ratio of the displacement amplitude of a reflected wave to that of the incident wave. Also called Reflectivity.
Reflection_Coefficient_Threshold	Reflection_Coefficient	Minimum reflection coefficient when processing the multiple reflections
Reflection_Heterogenity	Amplitude	An indirect measure of how much a reflection signal is changing or of how erratic a trace is. A constant has a Reflection_Heterogenity of 0. Heterogeneity can be computed from any of several signals, including seismic data, instantaneous phase, instantaneous frequency, apparent polarity and reflection strength.
Reflection_Intensity	Data_Valued_Property	Rate of flow of wave energy through a unit area perpendicular to the direction of wave travel; for a seismic wave, intensity is proportional to the square of the amplitude of displacement or velocity.
Reflection_Strength	Analytic_Trace	Amplitude of analytical seismic trace (Hilbert transform technique). Synonym of Instantaneous_Amplitude.
Reflection_Strength_Slope	Slope	Least squares slope (gradient) of reflection strength in an interval.
Refractive_Index	Data_Valued_Property	The ratio of the velocity of light in a vacuum to that in the medium in question.
Region_Of_Interest	Name	Geopolitical area of interest
Regularization_Factor	Data_Valued_Property	Factor used in T2 inversion (nuclear magnetic resonance logging) to ensure the continuity of the T2 distribution as a function of the signal to noise ratio.
Related_Sample_Type	Type	Type of related samples taken in the recombination set
Relation_Valued_Property	Property	A Property whose value is a reference (pointer) to another Entity.
Relationship_Constraint_Type	Type	Type of constraint for a relationship, such as Restrict, Cascade, or Nullify.
Relationship_Type	Type	Type of relationship between two objects: Containment, Reference, Supertype, Catalog,etc.
Relative_Apparent_Resistivity	Resistivity	The ratio of apparent resistivity to the true resistivity of a portion of a reservoir model (like a two-layer model).
Relative_Bearing	Plane_Angle	Angle measured clockwise from top of hole to tool angular reference point in the plane perpendicular to the tool axis, viewed from above the tool.
Relative_Dip_Angle	Dip_Angle	Magnitude of formation dip relative to structural dip; computed by subtracting structural dip from true dip (dip removal).
Relative_Dip_Azimuth	Dip_Azimuth	Azimuth of formation dip relative to structural dip; computed by subtracting structural dip from true dip (dip removal).
Relative_Permeability	Permeability	The ratio of effective permeability divided by the absolute permeability; e.g. the relative permeability of a rock to that of any of its contained fluids.
Relative_Permeability_Basis	Type	Absolute or effective permeability basis for the relative permeability.
Relative_Permeability_Function	Function_Name	Name of the function used to represent relative permeability.
Relative_Permeability_Function_Coeff	Coefficient	Coefficients used in the function.
Relative_Permeability_Gas	Relative_Permeability	Ratio of effective gas permeability to absolute permeability. Usually abbreviated as Krg
Relative_Permeability_Oil	Relative_Permeability	Ratio of effective oil permeability to absolute permeability. Usually abbreviated as Kro.
Relative_Permeability_Water	Relative_Permeability	Ratio of effective water permeability to absolute permeability. Usually abbreviated as Krw.
Relaxation_Time	Time_Interval	In nuclear magnetic resonance measurements, the time constant related to the rate at which nuclei realign to the static magnetic field after disturbance by a radio frequency pulse.
Relaxation_Time_Ratio	Ratio	In nuclear magnetic resonance logging, the ratio of longitudinal to transverse relaxation time; used to determine polarization correction.
Remaining_Life	Operating_Time	Remaining relative life predicted by the CoilLIFE model expressed as a percentage
Remaining_Volume	Volume	Volume of material which remains (e.g. remaining volume to be pumped)
Remarks	Data_Valued_Property	Any type of remarks added to an entity instance.
Remote_File	File_Name	Name of file on remote host
Report_Date	Date	Date (time) when report was completed or issued.
Report_Flag	Flag	Flag indicating the presence of a report, or that an item or event is to be included in a report.
Representation_Attribute	Attribute_Name	Object Attribute name where Representation may be found if not specified.
Representation_Code	Code	Catalog code of the Representation
Representation_Object	Object_Name	Object instance name where Representation may be found if not specified.
Representation_Type	Type	The type of computer representation used to manipulate a property value, e.g. Grid, Array, Primitive, etc.
Reservoir_Distance	Length	The distance between two features in a reservoir, for use in modeling the reservoir.
Reservoir_Fluid_Compressibility	Compressibility	Compressibility of the reservoir fluid
Reservoir_Fluid_Density	Density	The density of the reservoir fluid i.e. the mixture oil, gas and water.
Reservoir_Fluid_Viscosity	Viscosity	The viscosity of reservoir fluid at specific temperature and pressure conditions.
Reservoir_Gas_Oil_Ratio	Gas_Oil_Ratio	The ratio of gas to oil of the reservoir fluid at reservoir condition
Reservoir_Type	Type	Description of the reservoir type for a well test model.
Residual_Gas_Saturation	Saturation	The fraction or percentage of gas remaining following production from the reservoir.
Residual_Hydrocarbon_Saturation	Saturation	The fraction or percentage of hydrocarbons remaining following the production of hydrocarbons from the reservoir.
Residual_Hydrocarbon_Volume_Fraction	Hydrocarbon_Volume_Fraction	The volume fraction of residual hydrocarbons with respect to the total volume; residual hydrocarbons are those still in place in the flushed zone after the invasion process.
Residual_Oil_Saturation	Saturation	The fraction or percentage of oil remaining following the liberation of gases from the reservoir.
Residual_Water_Saturation	Saturation	The fraction or percentage of water remaining at maximum hydrocarbon saturation, as measured in core analysis. It differs from Irreducible_Water_Saturation because of filtrate invasion and gas expansion from the core being brought to the surface.
Resistance	Impedance	The resistance of a medium to the flow of electric current; the real component of the complex quantity Impedance.
Resistance_Gradient	Gradient	A measure of the change in electric resistance per unit length.
Resistive_Inclusion_Contrast	Conductivity_Contrast	Conductivity contrast between resistive inclusions and the surrounding rock
Resistive_Inclusion_Proportion	Inclusion_Proportion	Percentage of rock occupied by resistive inclusions within a given depth interval
Resistive_Inclusion_Size	Surface_Area	Average area of resistive inclusions as seen at the borehole wall
Resistivity	Data_Valued_Property	The property of a material which resists the flow of electrical current. The ratio of electric-field intensity to current density. The reciprocal of conductivity.
Resistivity_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a resistivity logging measurement.
Resistivity_Index	Ratio	The ratio of the resistivity of a formation to the resistivity it would have if 100% saturated with formation water (Rt/Ro).
Resistivity_K_Factor	Data_Valued_Property	K Factor, a function of the geometry of the electrode or sensor array of a resistivity measurement device.
Resistivity_Time_After_Bit	Time_After_Bit	In MWD/LWD logging, the time delay between the drill bit and a resistivity sensor reaching a given point in the wellbore.
Resolution	Multi_Use_Property	The smallest separation between two objects such that they can still be discerned as separate objects. In sensor technology, the smallest change in input which will produce a detectable change in output. In this context, it is the same as Sensitivity.
Resolution_Description	Description	Textual description of the qualified resolution, e.g., 0.005 psi at > 4 s sampling rate, 0.01 psi at 1 s sampling rate.
Response_Equation	Data_Valued_Property	Sensor response equation
Response_Frequency	Frequency	Instantaneous frequency at local maximum of reflection intensity
Response_Parameter	Multi_Use_Property	Property which reflects the response of some measurement device or algorithm to a particular material or environment. The Unit_Quantity is determined by the type of measurement.
Response_Phase	Instantaneous_Phase	Instantaneous phase at local maximum of reflection intensity
Response_Strength	Amplitude	Reflection strength at local maximum of reflection intensity
Restoring_Force	Force	The force required to restore initial conditions. For example, at the end of a test.
Reynolds_Number	Ratio	The ratio of inertial force to viscous force for viscous fluid flow.
Rheology_Model	Type	Mathematical model describing how the shear stress relates to the shear rate i.e. how a fluid flows and is deformed in response to applied stresses. Most popular model are Newtonian, Bingham Plastic and Power-Law
Rheometer_Deviation	Plane_Angle	Vector of deviation angles of the rheometer related to the vector of given Angular Velocity
Rig_Heading	Azimuth	Azimuth of the direction to which the rig is facing.
Rig_Heave	Height	Amplitude of the vertical motion of the rig
Rig_Pitch_Angle	Plane_Angle	Measure of the fore-aft rotational movement of the rig due the combined effects of wind and waves.
Rig_Roll_Angle	Plane_Angle	Measure of the side-to-side rotational movement of the rig due the combined effects of wind and waves; measured as the angle from vertical.
Right_Handed	Flag	Flag indicating that a 3D axis system is right-handed: a 3D coordinate system is Right_Handed if the direction of rotation from the x axis to the y axis is counter-clockwise when viewed from a positive position on the z axis. For example, if x is East and y is North, a Right_Handed system will have the positive z pointing upward (as increasing elevation). Right_Handed is meaningless for 2D systems.
Right_Hidden_Width	Width	For core images, the width of the core which is hidden on the right side of the image (by core box, for example).
Rights_Type	Type	Type of lease rights
Rigid_Flag	Flag	Flag indicating that a piece of equipment is rigid.
Riser_Angle	Plane_Angle	Angle of the marine riser with the vertical.
Riser_Internal_Diameter	Inside_Diameter	The internal diameter of the marine riser.
Riser_Tension	Tension	Tension of the marine riser
Rock_Class	Type	Classification of rocks into Chemical, Volcaniclastic, etc.
Rock_Code	Code	Catalog code of a rock type (e.g. Limestone)
Rock_Compressibility	Compressibility	Compressibility of the rock matrix.
Rock_Compressibility_Correlation	Name	Rock Compressibility Correlation (Sandstone, Carbonate)
Rock_Compressibility_Depth	Depth	Measured depth for which Rock Compressibility is stated.
Rock_Embedment_Strength	Strength	Force required to push a 1/8 inch diameter sphere 1/16 in into the rock. (Lab test). Value ranges from 5 to 20 kpsi for chalk, 40 to 100 kpsi for sandstones, 50 to 200 for Dolomites.
Rock_Genesis	Type	Classification of rocks by genetic origin, e.g. Sedimentary, Igneous, etc.
Rock_Solubility_In_Acid	Solubility	Amount of rock, normally expressed as a percentage by weight soluble in a given acid
Rock_Solubility_In_HCl	Rock_Solubility_In_Acid	Amount of rock, normally expressed as a percentage by weight soluble in HCl
Rock_Solubility_In_RMA	Rock_Solubility_In_Acid	Amount of rock, normally expressed as a percentage by weight soluble in Mud Acid (standard mixture of 12 % HCl and 3% HF)
Rock_Subclass	Type	Classification of rocks into Carbonate, Evaporite, etc. Commonly called Lithology.
Rotary_Speed	Angular_Velocity	Rotational speed of the Rotary Table.
Rotating_Weight	Hook_Load	Surface weight of the drillstring while drilling
Rotation	Plane_Angle	The angular displacement of a rotating body or figure.
Rotation_1	Rotation	Value of first rotation, as indicated by the first token in ROTATION_SENSE, used in transforming a coordinate system into a new (local) coordinate system.
Rotation_2	Rotation	Value of second rotation, as indicated by the second token in ROTATION_SENSE, used in transforming a coordinate system into a new (local) coordinate system.
Rotation_3	Rotation	Value of third rotation, as indicated by the third token in ROTATION_SENSE, used in transforming a coordinate system into a new (local) coordinate system.
Rotation_Gradient	Gradient	A measure of the rotation of an object per unit length; e.g., flowmeter rotation per length of pipe, pipe rotation per unit length (for stuck pipe applications.
Rotation_Sense	Type	Describes the sense of the axis system rotation specified by {ROTATION_1,ROTATION_2,ROTATION_3}. Most commonly used are "X_Y_Z" and "Z_NEWX_NEWZ".
Rotor_Lobe_Count	Count	Number of rotor lobes in a drill motor configuration (PDM only). Note: Stator is equal to rotor plus one.
Rotor_Number	Ordinal_Number	Number of the rotor. (For a cylindrical rheometer, each number corresponds to a different size. Standard Rotor is #1)
Roundness	Shape	A measure of the degree of how round an object is, such as a contour on a Surface.
Rover_Amplitude	Amplitude	Difference between seismic amplitude and the straight line connecting the two nearest extremes (with same kick).
Royalty	Money	Royalty received by lessor
Rugosity	Shape	A measure of surface irregularity, such as of the borehole wall.
Run_Number	Ordinal_Number	The number (or rank) associated with a particular run of a tool or activity. Use is discouraged due to ambiguity when services are combined or when complete history unavailable; time of data acquisition is more reliable.
Running_Direction	Type	Running direction of an equipment: Pulling Out Of Hole-POOH (Up=-1) or Running In Hole-RIH (Down=1)
Running_Force	Force	The force needed to run. For example, during a test.
Running_Length	Length	Sum of all the displacements in one direction (generally downhole) made by a downhole equipment. Used as fatigue indicator or charged item in coil tubing operations.
Running_Speed	Velocity	Speed of an equipment running into (counted positive) or out of the hole (counted negative).
SCAL_Flood_Direction	Direction	Direction of fluid flow through the sample in the laboratory (e.g. Horizontal, Downwards, Upwards). Water-oil experiments are almost always horizontal, gas-liquid experiments may be horizontal or vertical. If they are vertical they are done in the gravity stable direction. For example gas flooding an oil filled plug would be downwards, water flooding a gas filled plug would be upwards.
SDM_Domain_Name	Name	Name of the data domain, as described in the Schlumberger Data Model.
S_Wave_Angle	Plane_Angle	S-wave angle
Safety_Drill_Type	Type	Type of Quality, Health, Safety, and Environmental safety drill such as Fire Drill, Abandon Ship Drill, Spill Control Drill.
Safety_Factor	Data_Valued_Property	Amount by which some operating condition could be exceeded before reaching the theoretical operational limit, to allow for uncertainty in the actual upper limit. For upper limits, Operating Condition X (1 + Safety Factor) = Upper Limit.
Sale_Date	Date	Date of lease purchase
Sale_Group	Type	Within a business line, Sales services are gathered by group with technical commonalities.
Sale_Number	Identifier	Sale number of lease purchase
Salinity	Chemical_Concentration	Concentration of the total salts in solution (Na, K, Cl, So4, ..).
Samarium_Yield	Elemental_Yield	Elemental contribution of Samarium with respect to total.
Sample_Count	Count	Number of samples.
Sample_Gas_Oil_Ratio	Gas_Oil_Ratio	Ratio of gas flowrate to oil flowrate when a sample is taken
Sample_Interval	Data_Valued_Property	Index interval between sequential data samples; see also Depth_Increment and Time_Increment (Sampling_Period)
Sample_Number	Identifier	The number assigned to a formation or fluid sample.
Sample_Type	Type	Nature of the sample e.g. oil or gas
Sample_Water_Oil_Ratio	Water_Oil_Ratio	Water oil ratio when a sample is taken
Sampling_Bottle_Code	Code	Code for sampling bottle
Sampling_Bottle_Number	Identifier	Sample bottle number
Sampling_Bottle_Type	Type	Type of sampling bottle
Sampling_Duration	Time_Interval	Duration of data sampling or recording.
Sampling_End_Time	End_Time	End date/time of surface sampling
Sampling_Period	Time_Interval	Time interval between the recording of two sequential data samples.
Sampling_Start_Time	Start_Date	Starting date/time of surface sampling
Sand_Concentration	Solids_Concentration	Sand content per Mud Volume, API RP13B, Section 5, Sand
Sand_Volume_Fraction	Volume_Fraction	Volume fraction of sand as calculated, measured or inferred from formation properties.
Sandface_Flowing_Pressure	Pressure	The pressure in the formation immediately prior to entering any completion pressure drops.
Saturation	Data_Valued_Property	The fraction or percentage of the pore volume occupied by a specific fluid; e.g., oil, gas, water.
Saturation_Exponent	Exponent	The exponent of the Saturation term in the Archie saturation equation. Abbreviated "n".
Sayers_Anellipticity	Coefficient	Sayers' normalized anellipticity factor, an alternative to eta for describing the relationship between horizontal and moveout compressional velocities.
Scale_Factor	Coefficient	Coefficient used to convert or correct data, as to some standard.
Scale_Factor_Latitude	Latitude	Latitude at which scale factor is exact.
Scale_Factor_Longitude	Longitude	Longitude at which scale factor is exact.
Scale_X	Scale_Factor	Scale factor in X dimension
Scale_Y	Scale_Factor	Scale factor in Y dimension
Scale_Z	Scale_Factor	Scale factor in Z dimension
Scan_Type	Type	Describes the way in which a subject is scanned to take data samples or to generate an image.
Scheduled_Start_Time	Start_Time	Scheduled start time for an activity
Schoenberg_Ellipticity	Coefficient	Schoenberg's ellipticity factor, the ratio of horizontal to vertical velocity
Screen_Angle	Inclination	Angle of the screen, with respect to horizontal
Screen_Arrangement	Type	Position of the screens, such as in a shale shaker.
Screen_Count	Count	Number of Screens
Screen_Mesh_Size	Diameter	Size of the mesh (usually expressed in inches) use to filter particles.
Screen_Motion	Type	An indicator of the current state of the movement induced by the vibrator(s) of a shale shaker screen
Screen_Tension_Type	Type	Type of screen tension (deck tensioned or factory pretensioned)
Second_Derivative	Gradient	Gradient of gradient of a scalar function
Secondary_Porosity	Porosity	The additional porosity created by chemical changes, specially fissures, fractures, solution vugs and dolomitization.
Section_Length	Length	Length of one section, such as the nominal length of one section of a streamer.
Section_Number	Identifier	Jeffersonian Section Number
Section_Suffix	Name	A subsection single letter suffix designation a part of a Section, as used in California, USA
Section_Type	Type	Jeffersonian Section Type such as a Lot
Sediment_And_Water	Ratio	Measure of impurities which are contained in oil produced from a well, as described in ASTM Standard Test D96-82. Traditionally called Basic Sediment and Water.
Sedimentary_Channel_Type	Type	The type of the sedimentary environment that created the channel, e.g. Submarine, Stream, Tidal, etc.
Sedimentary_Feature_Type	Type	The type of the sedimentation feature associated with a subsurface or surface Earth region.
Sedimentary_Structure_Type	Type	The type of sedimentary structure associated with an interval.
Sedimentary_Unit_Type	Type	The type of sedimentary unit e.g. channel, bar, etc.
Segment_Length	Interval_Length	The length of a borehole segment.
Seismic_Arc_Length	Acoustic_Amplitude	A measure of reflection heterogeneity which is used to quantify lateral changes in reflection patterns. Used as a stratigraphic sequence indicator.
Seismic_Flag	Flag	Flag indicating that the object or data pertains to seismic techniques or was derived from seismic data.
Seismic_Object_Type	Type	Type of seismic data object: data or survey geometry, 2 or 3D
Seismic_Offset	Length	The distance between source and receiver or geophone (seismic).
Seismic_Vertical_Depth	True_Vertical_Depth	Vertical Depth from Seismic Reference Datum
Semblance	Coherence	A measure of waveform coherence with respect to slowness and time, computed as a function of coherent energy to total energy; also called "Slowness_Time_Coherence"
Semi_Major_Axis	Radius	Length of semi-major axis of an ellipse; in geodetic work, of a reference ellipsoid.
Semi_Minor_Axis	Radius	Length of semi-minor axis of an ellipse; in geodetic work, of a reference ellipsoid.
Sensitivity	Multi_Use_Property	The ratio of sensor or instrument output to input.
Sensitivity_To_Temperature	Sensitivity	Sensitivity to temperature variation for a sensor
Sensor_Azimuth	Azimuth	The azimuth of a sensor on a logging device, used to determine the orientation of the device.
Sensor_Code	Code	Sensor code
Sensor_End_Time	End_Time	End time (tend) as observed by downhole or surface sensors, measured as elapsed time since the Time Reference.
Sensor_Number	Ordinal_Number	Sensor number
Sensor_Standoff	Standoff	The distance from a sensor to the medium being investigated, such as from a logging sonde to the wall of the borehole.
Sensor_Start_Time	Start_Time	Start time (t0) as observed by downhole or surface sensors, measured as elapsed time since the Time Reference.
Sensor_Type	Type	Type of sensor used to acquire data
Separator_Code	Code	Code for the separator
Separator_Gas_Capacity	Gas_Flowrate	Gas separator capacity at maximum working pressure and 1 minute retention time at low liquid level (MMscf/day)
Separator_Line	Type	Type of separator line: e.g. oil outlet, gas outlet, water outlet or inlet
Separator_Liquid_Capacity	Liquid_Flowrate	Liquid separator capacity at maximum working pressure and 1 minute retention time at high liquid level
Separator_Oil_Flowrate	Oil_Flowrate	Oil flowrate at separator conditions when a sample is taken
Separator_Pressure	Pressure	Pressure of the separator when a sample is taken
Separator_Temperature	Temperature	Temperature of the separator when a sample is taken
Separator_Type	Type	Separator type
Sequence_Boundary_Type	Type	The type of a Sequence Boundary in the Earth subsurface, e.g. Toplap, Concordance, Baselap, etc.
Sequence_Lower_Limit_Type	Type	The type of surface situated at the base of a sequence.
Sequence_Number	Ordinal_Number	Number used to identify or index an element in a sequence.
Sequence_Order	Type	The order of a sequence in the depositional process.
Sequence_Surface_Type	Type	The type of surface bounding a particular sequence.
Sequence_Trend	Type	The type of vertical evolution recognized in a particular sequence e.g. fining up.
Sequence_Type	Type	The type of sequence, e.g. granulometry, thickness, facies, etc.
Sequence_Upper_Limit_Type	Type	The type of limit bounding the top of a sequence.
Serial_Number	Identifier	The serial number placed on a piece of equipment.
Service_Code	Code	MIS Code of the service and unique identifier.
Service_Date	Date	The date on which a service was performed.
Service_Type	Type	Type of service
Session_Duration	Duration	Elapsed time from the start to the finish of a recording or processing session.
Setting_Force	Force	Load which must be applied to set compression type packer. Typical value : 10,000 lbf
Setting_Mode	Type	Mode for setting a plug or packer: by compression or inflation
Setting_Tool	Type	Generic type of plug or packer setting tool: Drill-Pipe or Wireline
Settled_Proppant_Height	Height	Height of the settled bank of proppant within a fracture, otherwise named pack height.
Shale_Volume_Fraction	Volume_Fraction	Volume fraction of shale as calculated, measured or inferred from formation properties.
Shallow_Conductivity	Conductivity	The conductivity which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids which are comprised primarily of mud filtrate.
Shallow_Induction_Conductivity	Shallow_Conductivity	The conductivity, measured by an induction log, which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids which are comprised primarily of mud filtrate.
Shallow_Induction_Resistivity	Shallow_Resistivity	The resistivity, measured by an induction log, which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids which are comprised primarily of mud filtrate.
Shallow_Lateral_Resistivity	Shallow_Resistivity	Resistivity measurement using a "lateral" electrode arrangement with a "shallow" investigation radius (several inches into the formation).
Shallow_Laterolog_Conductivity	Shallow_Conductivity	The conductivity, measured by a laterolog (or guard log) resistivity device, which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids which are comprised primarily of mud filtrate.
Shallow_Laterolog_Resistivity	Shallow_Resistivity	The resistivity, measured by a laterolog (or guard log) resistivity device, which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids which are comprised primarily of mud filtrate.
Shallow_Normal_Resistivity	Shallow_Resistivity	Shallow Resistivity measurement using a "normal" electrode arrangement.
Shallow_Resistivity	Resistivity	The resistivity which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids which are comprised primarily of mud filtrate.
Shank_Diameter	Outside_Diameter	Outer diameter of the equipment shank; for a drill bit, the shank is the portion of the bit body between the threaded connection and the base of the bit leg (for roller cone bits) or bit crown (for fixed cutter bits).
Shank_Length	Length	Length of the equipment shank; for a drill bit, it is the distance from the face of the bit connection to the base of the bit leg (for roller cone bits) or bit crown (for fixed cutter bits).
Shape	Geometry	A visible makeup characteristic of a particular item or kind of item. Also the spatial form of an item, or a standard or universally recognized spatial form.
Shape_Code	Array_Code	Catalog-controlled code of an array Shape.
Shape_Factor	Geometrical_Factor	A geometrical factor (Ca) characteristic of the reservoir areal drainage shape (e.g. circle or square) and the well location (e.g. centered).
Shear_Compressional_Slowness_Ratio	Ratio	Ratio of shear slowness (Shear_Slowness) to compressional slowness (Compressional_Slowness).
Shear_Compressional_Velocity_Ratio	Ratio	Ratio of velocity of Shear wave (Vs) to that of Compressional wave (Vp).
Shear_Modulus	Elastic_Modulus	The stress-strain ratio for simple shear. Also called rigidity modulus or Lame's constant.
Shear_Slowness	Acoustic_Slowness	Acoustic slowness of a shear wave (Vs); reciprocal of Shear_Velocity; a shear wave is a type of seismic wave in which the particle motion is perpendicular to the direction of propagation; also called S-wave or secondary wave.
Shear_Strain	Strain	Shear component of the change in dimensions caused by stress, generally expressed as a unitless ratio.
Shear_Stress	Stress	Shear force (shear: strain that causes contiguous parts of a body to slide relatively to each other in a direction parallel to their plane of contact) per area unit of surface
Shear_Velocity	Acoustic_Velocity	The velocity of a shear wave (Vs); a shear wave is a type of seismic wave in which the particle motion is perpendicular to the direction of propagation; also called S-wave or secondary wave.
Shear_Velocity_Gradient	Gradient	A measure of the change in the shear velocity of a medium per unit length.
Shock_Level	Indicator	Qualitative indicator of Shock_Rate; used as a real-time indicator of vibration severity for MWD/LWD tools.
Shock_Rate	Frequency	Measure of shocks or vibrations above some threshold per unit of time; used to quantify vibration severity for MWD/LWD tools.
Short_Name	Name	Informal, usually shortened name given to an object or data item; a nickname.
Shotsequence_Number	Ordinal_Number	Nominal ordering matching raw receiver sort
Show_Description	Description	A textual description of the hydrocarbon shows in a rock sample.
Show_Distribution	Description	A textual description of the distribution of hydrocarbon indicators on a rock surface; e.g. solid, spotty, streaky.
Show_Flow_Rate	Description	A textual description of the rate at which fluid emerges from the rock sample. Example keywords include: dead oil, live show, streaming or bleeding.
Show_Quality	Description	A qualitative indicator of the intensity of the fluid show.
Show_Type	Type	The type of hydrocarbon show from a Well or from a Sample (Core, Cuttings, etc.): e.g. Gas, Oil, etc.
Shrinkage_Factor	Volume_Fraction	A measure of the decrease in volume of the liquid phase caused by release of solution gas and/or by the thermal contraction of the liquid; the reciprocal of formation volume factor.
Siderite_Volume_Fraction	Volume_Fraction	The volume fraction of siderite with respect to the total volume.
Sidetrack_Number	Identifier	A sequential number identifying a particular sidetrack; 0 if no sidetracks have occurred. Used for WITS Channel SKNO.
Signal_Amplitude	Amplitude	The amplitude associated with a generic type signal.
Signal_To_Noise_Ratio	Ratio	The ratio of signal amplitude to noise amplitude, usually expressed in dB.
Signal_Type	Type	Type of data signal.
Silicon_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of silicon to total dry weight
Silicon_Yield	Elemental_Yield	Elemental contribution of Silicon with respect to total.
Silt_Volume_Fraction	Volume_Fraction	The volume fraction of silt with respect to the total volume.
Simulation_Layer_Name	Name	Name given to a layer in a reservoir simulation model.
Simulation_Multiple_Count	Count	Number of multiple reflections considered in the simulation
Single_Shot_Flag	Flag	If flag is set, it means that the equipment or item can only be used once before rework or replacement.
Skin_Factor	Data_Valued_Property	The term that accounts for additional pressure drops in the immediate vicinity of a well in well performance calculations. A positive skin indicates damaged conditions, negative indicates stimulated conditions.
Slackoff_Friction_Coefficient	Coulomb_Friction_Coefficient	Friction coefficient between a string and the pipe when running into the hole
Slackoff_Hook_Load	Hook_Load	Average slackoff hook load (slackoff weight) over the reporting period.
Slackoff_Reel_Back_Tension	Tension	Amount of tension kept on the coiled tubing between the gooseneck and the reel while going into the hole
Slant_Rig_Angle	Plane_Angle	Slant rig angle
Slant_Rig_Flag	Flag	A flag indicating if the rig is slanted.
Slew_Rate	Data_Valued_Property	Highest rate of change in signal level which a device can produce; also the rate at which a device reacts to commands. In the latter case, the data are normally represented in units of time.
Sliding_Window_Duration	Time_Interval	Duration (length) in time of the sliding window used for processing.
Slippage_Velocity	Flow_Velocity	In two-phase flow, the difference between the velocities of the two phases.
Slope	Multi_Use_Property	The slope of a function: the tangent of the angle between the x-axis and the tangent to the curve defined by the function.
Slot_Width	Width	Width of a slot, such as in a slotted liner.
Slowness_Time_Coherence	Coherence	A measure of waveform coherence with respect to slowness and time, computed as a function of coherent energy to total energy; also called "Semblance"
Small_Circle_Azimuth	Azimuth	The azimuth of the pole associated with a small circle.
Small_Circle_Dip	Dip_Angle	The angle of the pole associated with a small circle.
Smectite_Volume_Fraction	Volume_Fraction	The volume fraction of smectite with respect to the total volume.
Smoothing_Mode	Processing_Option	Mode to use while smoothing horizon picks (automatic, manual).
Snap_Criteria	Data_Mask	Set of parameters used by an application for "snapping" interpretation values to their corresponding data samples
Snap_Depth_Window_Bottom	Snap_Window_Bottom	Distance below the picked Z to search for the Tracking Event and Snap_Type when snapping
Snap_Depth_Window_Top	Snap_Window_Top	Distance above the picked Z to search for the Tracking Event and Snap_Type when snapping
Snap_Quality	Quality_Indicator	Indicates whether the values are snapped to a sample or sub-sample
Snap_Type	Type	When snapping to the Seismic Event Type the application should snap to the Largest or Closest (Valid only for peak or trough)
Snap_Window_Bottom	Offset	Interval (time or depth) below the picked Z to search for the Tracking Event and Snap_Type when snapping
Snap_Window_Top	Offset	Interval (time or depth) above the picked Z to search for the Tracking Event and Snap_Type when snapping
Sodium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of sodium to total dry weight
Sodium_Yield	Elemental_Yield	Elemental contribution of Sodium with respect to total.
Solids_Concentration	Concentration	Solid Concentration (Cutting, clays, polymer) per fluid Volume
Solids_Control_Cone_Count	Count	Number of cones of a solid Control Equipment
Solids_Control_Cone_Diameter	Diameter	Largest Inner Diameter of a Cone
Solubility	Data_Valued_Property	A measure of the amount of one substance (the solute) which will dissolve in a given amount of another (the solvent).
Solution_Gas_Liquid_Ratio	Gas_Liquid_Ratio	The ratio of dissolved gas volume to total liquid (oil + water) volume
Solution_Gas_Oil_Ratio	Gas_Oil_Ratio	Measure of the degree to which a gas is soluble in oil; ratio of the dissolved gas volume to liquid hydrocarbon volume, often designated Rs Oil
Solution_Gas_Oil_Ratio_Correlation	Type	Model used to compute gas solubility in oil
Sonde_Error	Error	An unwanted portion of the total conductivity measurement of an induction logging instrument, generated by imperfections in the coils in the sonde. It is measured during surface calibration and then cancelled during the survey operation.
Sonic_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a sonic logging measurement.
Sonic_Porosity	Apparent_Porosity	Porosity calculated using the acoustic slowness measurement from a sonic log.
Sonic_Porosity_Dolomite	Sonic_Porosity	Porosity calculated using the compressional wave travel time measurement from an acoustic log with a dolomite matrix travel time.
Sonic_Porosity_Limestone	Sonic_Porosity	Porosity calculated using the compressional wave travel time measurement from an acoustic log with a limestone matrix travel time.
Sonic_Porosity_Sandstone	Sonic_Porosity	Porosity calculated using the compressional wave travel time measurement from an acoustic log with a sandstone matrix travel time.
Sonic_Time_After_Bit	Time_After_Bit	In MWD/LWD logging, the time delay between the drill bit and a sonic sensor reaching a given point in the wellbore.
Source	Data_Valued_Property	The source of an entity instance, usually a user name or an application (or activity) instance.
Source_Angle	Plane_Angle	Source angle
Source_File	File_Name	File containing the original description of the object, e.g., TIF file for an image.
Source_Line_Position	Cylindrical_Position	Position in a source line.
Source_Line_Rho	Radius	Horizontal (x-y) distance from origin of position in a source line.
Source_Line_Theta	Theta_Angle	Horizontal angle of position in a source line, measured counter-clockwise from x-axis.
Source_Line_Z	Z_Coordinate	Z-coordinate of position in a source line.
Source_Offset	Seismic_Offset	The distance to the seismic source from some other object, such as a wellbore in VSP work.
Source_Orientation	Spherical_Position	Downhole source orientation vector.
Source_Orientation_Phi	Inclination	Vertical angle of downhole source, measured from the x-y plane.
Source_Orientation_Rho	Radius	Horizontal (x-y) distance from origin of downhole source.
Source_Orientation_Theta	Theta_Angle	Horizontal angle of downhole source, measured counter-clockwise from x-axis.
Spacing_X	Interval_Length	Spacing in X dimension; may be expressed as an absolute spacing with units or as a proportion of some reference X Spacing.
Spacing_Y	Interval_Length	Spacing in Y dimension; may be expressed as an absolute spacing with units or as a proportion of some reference X Spacing.
Spacing_Z	Interval_Length	Spacing in Z dimension; may be expressed as an absolute spacing with units or as a proportion of some reference X Spacing.
Sparse_2D_Data	Data_Valued_Property	A data set of sparse location data in 2-space, where none or up to n Properties may be represented at each location. Example: X_Coordinate,Y_Coordinate,Porosity,Density.
Sparse_3D_Data	Data_Valued_Property	A data set of sparse location data in 3-space, where none or up to n Properties may be represented at each location. Example: X_Coordinate,Y_Coordinate,Z_Coordinate,Velocity.
Spatial_Gamma_Radiation_Intensity	Gamma_Ray	Intensity of gamma radiation represented as a function of a spatial path.
Species	Biological_Name	A category of biological classification ranking immediately below the genus or subgenus.
Specific_Gravity	Density	The ratio of the density of a substance to the density of some other substance taken as a standard (e.g. water, hydrogen).
Specific_Heat	Data_Valued_Property	The amount of heat in calories required to raise the temperature of 1 gram of substance by 1 degree Celsius.
Specific_Productivity_Index	Mobility	Rate of fluid produced per unit change in limiting pressure per unit of reservoir thickness. For oil wells, PIs is normally expressed in barrels per day per psi per foot of net reservoir thickness.
Specific_Surface_Area_Per_Mass	Data_Valued_Property	The characteristic of a porous media which is the internal surface area of the medium per unit mass.
Specific_Surface_Area_Per_Volume	Data_Valued_Property	The characteristic of a porous media which is the internal surface area of the medium per unit volume.
Specific_Volume	Data_Valued_Property	A measure of the volume distribution of a gas or liquid per unit mass.
Spectral_Fluorescence_Intensity	Data_Valued_Property	Intensity of light emitted by a material represented as a function of emitted light wavelength and wavelength of the excitation beam, typically an ultraviolet light source.
Spectral_Gamma_Radiation_Intensity	Gamma_Ray	Intensity of gamma radiation represented as a function of wavelength.
Spherical_Mobility	Mobility	A measure of the ease with which a fluid can be moved in a specific medium (i.e. rock); computed as the cube root of (Vertical_Mobility X Horizontal_Mobility**2)
Spherical_Permeability	Directional_Permeability	An effective permeability used to combine directional permeabilities, Kx and Ky. Usually abbreviated as Ksph.
Spherical_Position	Location	Set of coordinates specifying the position of a point in a spherical coordinate system
Spherically_Focused_Conductivity	Shallow_Conductivity	The conductivity, measured by a spherically focused log, which represents the resistivity approximately one to two feet into the formation.
Spherically_Focused_Resistivity	Shallow_Resistivity	The resistivity, measured by a spherically focused log, which represents the resistivity approximately one to two feet into the formation.
Sphericity	Shape	A measure of the degree of how spherical an object is, such as an Lens within a subsurface Volume
Spinner_Speed	Angular_Velocity	Rotational speed of the flowmeter spinner.
Spliced	Modifier	The data related to the property has been obtained by concatenating two or more other data sources.
Spontaneous_Potential	Electric_Potential	The potential difference (DC voltage) between a movable electrode in the borehole and a distant reference electrode usually at surface. The voltage is due to currents generated by the Electrochemical and Electrokinetic potentials.
Spontaneous_Potential_Drift	Gradient	The drift in the measured Spontaneous Potential per depth.
Spore_Color_Index	Color	Relative color of fossil spores as caused by thermal processes. Index is used as an indicator of thermal maturation of organic material.
Spot_Description	Description	The fractional part of interest within the section
Spring_Number	Ordinal_Number	Spring number of a cylindrical rheometer corresponding to a particular stiffness. Fann 35 spr #1stiffness is 2.2116E-3 Nm/Rad
Spring_Stiffness	Data_Valued_Property	Coefficient relating spiral spring exerted force and corresponding elongation
Spud_Date	Date	The date a spud attempt was performed on a well
Spurt	Length	(Fracturing) Volume of fluid flowing through a given area of porous media which leaks off during the formation of the filter cake. Spurt loss reduces the fluid volume available for fracture extension. Typical Unit: gal/100ft2.
Squared	Modifier	The data related to the property is the result of a squaring process, i.e., a process that converts a smooth function into a step function.
Stab_To_Bottom_Conn_1	Length	Length from the mid-point of the first stabilizer to the bottom connection of the tool
Stab_To_Bottom_Conn_2	Length	Length from the mid-point of the second stabilizer to the bottom connection of the tool
Stab_To_Bottom_Conn_3	Length	Length from the mid-point of the third stabilizer to the bottom connection of the tool
Stable_Elapsed_Time	Time_Interval	Time elapsed since production conditions were stable
Stack_Alkhalifah_Eta	Alkhalifah_Eta	Effective value through the subsurface of Alkhalifah's eta anisotropy parameter.
Stack_Anisotropic_Axis_1_Crossline_Direction	Anisotropic_Axis_1_Crossline_Direction	Estimation of the anisotropic axis 1 crossline direction for all layers to the current depth.
Stack_Anisotropic_Axis_1_Inline_Direction	Anisotropic_Axis_1_Inline_Direction	Estimation of the anisotropic axis 1 inline direction for all layers to the current depth.
Stack_Anisotropic_Axis_2_Crossline_Direction	Anisotropic_Axis_2_Crossline_Direction	Estimation of the anisotropic axis 2 crossline direction for all layers to the current depth.
Stack_Anisotropic_Axis_2_Inline_Direction	Anisotropic_Axis_2_Inline_Direction	Estimation of the anisotropic axis 2 inline direction for all layers to the current depth.
Stack_Bale_Kappa	Bale_Kappa	Effective value through the subsurface of Bale's kappa, the mode-converted wave equivalent to eta, describing the relationship between horizontal and moveout mode-converted wave velocities.
Stack_Bale_Xi	Bale_Xi	Effective value through the subsurface of Bale's xi, the shear wave equivalent to eta, describing the relationship between horizontal and moveout shear wave velocities.
Stack_Crossline_Dip	Crossline_Dip	Estimation of the crossline dip for all layers to the current depth.
Stack_Inline_Dip	Inline_Dip	Estimation of the inline dip for all layers to the current depth.
Stack_Mode_Converted_Velocity	Mode_Converted_Velocity	Stacking converted-wave velocity, for a wave traveling through layers as a Compressional wave in one direction and a Shear wave in the other. This can be computed from a combined RMS average of the Compressional and Shear interval velocities. In practice it is usually determined directly from velocity analysis on short offset converted wave data.
Stack_Number	Ordinal_Number	Stack number
Stack_Polarization_Azimuth	Polarization_Azimuth	Estimation of the polarization azimuth angle for all layers to the current dept.
Stack_Sayers_Anellipticity	Sayers_Anellipticity	Effective value through the subsurface of Sayers' normalized anellipticity factor.
Stack_Schoenberg_Ellipticity	Schoenberg_Ellipticity	Effective value through the subsurface of Schoenberg's ellipticity factor, for each layer.
Stack_Shear_Velocity	Shear_Velocity	Stacking shear wave velocity computed from an RMS average of the Shear interval velocities. In practice it is often determined from velocity analysis on Shear wave data, or indirectly from the stacking velocities for Compressional and Converted wave data.
Stack_Thomsen_Delta	Thomsen_Delta	Effective value through the subsurface of Thomsen's delta anisotropy parameter.
Stack_Thomsen_Epsilon	Thomsen_Epsilon	Effective value through the subsurface of Thomsen's epsilon anisotropy parameter.
Stack_Thomsen_Gamma	Thomsen_Gamma	Effective value through the subsurface of Thomsen's gamma anisotropy parameter.
Stack_Thomsen_Sigma	Thomsen_Sigma	Effective value through the subsurface of Thomsen's sigma anisotropy parameter
Stack_Velocity	Acoustic_Velocity	The velocity determined from velocity analysis based upon normal-moveout measurements.
Stack_Velocity_Ellipticity_Azimuth	Velocity_Ellipticity_Azimuth	Estimation of the velocity ellipticity azimuth for all layers to the current depth.
Stack_Velocity_Ellipticity_Flattening	Velocity_Ellipticity_Flattening	Estimation of the velocity ellipticity flattening for all layers to the current depth.
Stacked	Modifier	The data related to the property is the sum of two or more other data sources.
Stacked_Time_Interpretation	Time_Interpretation	Seismic traveltime interpretation based on stacked seismic sections
Stacking_Method_Type	Method_Type	Stacking method (e.g. median, average, auto, manual)
Stage_Count	Count	Number of stages in an activity.
Stage_Volume	Volume	Volume of material pumped during a stage of an activity.
Standard_Deviation	Statistical_Property	Statistical standard deviation from the mean value for some data; normally abbreviated a lowercase sigma; the unit quantity is determined by that of the data.
Standard_Document_Identifier	Identifier	Standard document identifier, such as an ISBN or ISSN number.
Standard_Oil_Flowrate	Oil_Flowrate	Oil flow rate at standard condition when a sample is taken
Standard_Pressure	Pressure	Pressure considered to be "standard", for rates and volumes reported to be measured at Standard Conditions.
Standard_Reference_Datum	Depth	Depth measured from the Standard Reference Datum
Standard_Temperature	Temperature	Temperature considered to be "standard", for rates and volumes reported to be measured at Standard Conditions.
Standing_Oil_Flag	Flag	Indicates if there is standing, motionless oil
Standing_Water_Flag	Flag	Indicates if there is standing, motionless water
Standoff	Length	The amount of physical separation between two objects, usually maintained in order to control their interaction.
Standoff_Porosity	Apparent_Porosity	Porosity measurement of the "standoff" region, a very shallow porosity determination used to correct formation porosity measurements from nuclear logging tools.
Standoff_Ratio	Standoff	A measure of standoff of tubular equipment from the borehole wall, computed as the ratio of Standoff to the difference between hole radius and tubular radius; Standoff Ratio is 0 if the tubular is in contact with the hole wall, 1 if the tubular is centered in the hole.
Standpipe_Pressure	Pressure	Mud pressure at the stand pipe manifold, just before the flexhose connecting to the swivel.
Start_Age	Geologic_Age	The earliest (numerically largest) geologic or geochronologic age associated with an event or item, such as an earth layer, a fossil or pollen type.
Start_Age_Code	Geologic_Age_Code	The code of the earliest geologic or geochronologic age associated with an event or item, such as an earth layer, a fossil or pollen type.
Start_Date	Date	The date/time a particular activity started.
Start_Depth	Depth	Depth at which an activity starts e.g. at the beginning of the Coiled tubing pumping stage, depth of the cleaning tool
Start_Time	Absolute_Time	The time a certain activity or sub-activity started. Use Start_Age for geochronological time.
Starting_Force	Force	The force applied at the start of a process. For example, at the beginning of a test.
State_Code	Geopolitical_Region_Code	Catalog-controlled code of a State
State_Name	Name	Name of a State
Static_Potential	Pressure	Static (built up) pressure of a hydraulic unit, converted to pressure potential at a reference datum depth.
Static_Pressure	Pressure	Static (non-flowing) Pressure
Static_Pressure_Date	Date	Date when Static Pressure data were recorded
Station_Inflection	Flag	Logical flag for each seismic station indicating whether or not it is an inflection point
Station_Number	Ordinal_Number	Depth identifier
Station_Residual_Static	Data_Valued_Property	Residual static information (time) for each station
Statistical	Modifier	A Modifier of a property which is derived from the statistical analysis of, and which is used to characterize, another property.
Statistical_Property	Data_Valued_Property	A property of statistical nature, e.g. Standard Deviation, Average or Mean, Median, etc.
Statistical_Skewness	Statistical_Property	A statistical measure of asymmetry in a distribution.
Status	Indicator	An indicator of the state of an entity or process at some moment in time. Also the position or rank in relation to others.
Std_Parallel	Latitude	Latitude of parallel along which scale is true.
Std_Parallel_1	Latitude	First line of latitude along which scale is true, for map projections using two standard parallels; this parallel is NEAREST to the EQUATOR.
Std_Parallel_2	Latitude	Second line of latitude along which scale is true, for map projections using two standard parallels; this parallel is NEAREST to the POLE.
Steel_Grade	Grade	Grade used to qualify the characteristics of the steel. For tubulars, grade determines the minimum yield strength and thus the burst and collapse pressures and is of importance for the proper choice of slips. The grade can be either custom, i.e. defined by the supplier, e.g. US Steel FS80, Vallourec 110 VS 22, or defined by the API, e.g. C75, J55, N80, E. Number in the API grade means the minimum yield strength in kpsi (N80: 80,000 psi). API grades for Tubing, Casing and Drill pipes can be found in the API specifications 5xx.
Stiffness	Data_Valued_Property	The ratio of stress acting in a specified direction to the strain in a specified direction. Stiffness is a tensor of rank 4, but is expressible as a 6x6 matrix, the inverse of the compliance matrix.
Stoneley_Slowness	Acoustic_Slowness	The acoustic slowness of a Stoneley wave; a Stoneley wave is a type of seismic wave which is propagated along an interface, such as a tube wave in a borehole.
Stoneley_Velocity	Acoustic_Velocity	The velocity of a Stoneley wave; a Stoneley wave is a type of seismic wave which is propagated along an interface, such as a tube wave in a borehole.
Stop_Date	Date	The date a particular activity stopped.
Stop_Depth	Depth	Depth at which a particular activity stopped.
Stop_Time	Absolute_Time	The time a certain activity or sub-activity stopped.
Storage_Capacity	Volume_Fraction	The ratio of the sum of layer porosity thicknesses to total system porosity thicknesses for layered porous media.
Storage_Label	Identifier	Label found on any stored item, such as tapes, documents, etc.
Storage_Location	Location	The name of the location where an item is physically stored.
Storativity	Data_Valued_Property	Product of Porosity and Total Compressibility for a reservoir hydraulic unit.
Storativity_Ratio	Ratio	Ratio of component storativity to total system storativity. Usually known as Omega in reservoir dynamics.
Storativity_Thickness	Data_Valued_Property	The product of the Storativity of a layer and its thickness [phiCth].
Storativity_Thickness_Ratio	Ratio	Ratio of component storativity-thickness to total system storativity-thickness [phiCth(i) / phiCth(total)].
Strain	Data_Valued_Property	Measure of the change in dimensions or shape caused by stress, generally expressed as a unitless ratio of the change of length per unit of initial length. If not otherwise specified, strain is taken to be "normal" (in the same direction as the stress).
Streamer_Length	Length	The nominal length of the streamer.
Street_Address	Address	Physical location of a business, residence, or other installation, as would be used by a courier service or visitor to locate the installation.
Strength	Pressure	A measure of the ability of a body to resist applied force.
Stress	Data_Valued_Property	Force acting per unit area in a material resisting the stretching, compression or shear induced by external forces; fully characterized by a Stress_Tensor.
Stress_Gradient	Gradient	Change in stress magnitude over distance.
Stress_Tensor	Stress	A second rank tensor whose components are the stresses exerted across surfaces perpendicular to the coordinate directions.
Stretch	Length	The amount of elongation observed in an object as a result of its being placed under tension.
Stretch_Coefficient	Indicator	The amount of stretch per unit force applied.
Stripper_Friction_Load	Load	Amount of friction between the coiled tubing and the packoff assembly. It is not the hydraulic pressure within the Stripper.
Stroke_Count	Count	Cumulative number of strokes over a time interval
Stroke_Length	Length	Length of stroke (maximum travel), such as for a pump piston or for hydraulic jars).
Stroke_Rate	Count_Rate	Frequency of the piston (plunger) of a pump usually expressed in number of strokes per minute
Stroke_Volume	Volume	Volume of a pump stroke
Strontium_Yield	Elemental_Yield	Elemental contribution of Strontium with respect to total.
Structural_Dip_Removal_Flag	Processing_Option	This property specifies whether the effect of structural dipping on a particular geological zone has been removed.
Structural_Dip_Type	Type	This property specifies whether the structural dip is constant, variable or contemporaneous.
Structural_Model_Type	Type	Structural hypothesis chosen to derive the cross section
Subgenus	Biological_Name	A category in biological taxonomy below a genus and above a species.
Subsea_Equipment_Type	Type	Type of subsea equipment installed in facility or used in activity.
Subsea_Vertical_Depth	True_Vertical_Depth	Vertical Depth from Mean Sea Level
Sulfur_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of sulfur to total dry weight
Sulfur_Yield	Elemental_Yield	Elemental contribution of Sulfur with respect to total.
Sum_Amplitude	Amplitude	Sum of the amplitudes
Sum_Magnitude	Magnitude	Sum of magnitudes
Sum_Negative_Amplitude	Sum_Amplitude	Sum of amplitudes less than zero.
Sum_Positive_Amplitude	Sum_Amplitude	Sum of amplitudes greater than zero.
Summed_Traces_Number	Count	Number of traces in stack
Super_Array_Code	Array_Code	Code of super array
Supervised_Flag	Flag	Flag indicating whether the activity was supervised (1) or unsupervised (0)
Supplier	Organization_Name	Supplier name of a Product.
Surface_Area	Data_Valued_Property	Measure of the two-dimensional extent of the surface of some object.
Surface_Cable_Tension	Tension	Tension of the logging cable as measured at the surface.
Surface_Gas_Flowrate	Gas_Flowrate	Gas flowrate (surface conditions)
Surface_Lines_Volume	Volume	Total volume of the surface lines equipment
Surface_Location	Location	The location of a well, region, or facility/measurement point at the surface of the Earth.
Surface_Oil_Flowrate	Oil_Flowrate	Oil flowrate (surface conditions)
Surface_Reflection_Coefficient	Reflection_Coefficient	Reflection coefficient for the case when the multiples are reflecting from the free surface
Surface_Sensor_Code	Code	Specific code of surface sensor.
Surface_Sensor_Type	Sensor_Type	Type of surface sensor such as depth sensor, hydraulics depth sensor, kelly revolution sensor, etc.
Surface_Surface_Intersection_Type	Type	The type of Surface-Surface intersection showing the types of the 2 intersecting surfaces.
Surface_Temperature	Temperature	Temperature above ground. Temperature of the atmosphere.
Surface_Type	Type	The type of an Earth surface in the subsurface Earth structure, e.g. Fault, Horizon, Boundary, etc.
Surface_Water_Flowrate	Water_Flowrate	Water flowrate (surface conditions)
Survey_Bearing	Plane_Angle	The horizontal angle of an object, measured as a departure from some datum direction, such as North or South. Representations typically indicate the datum and the direction of measurement, such as [N 26.46(deg) W].
Survey_Bottom_Depth	Bottom_Depth	Deepest depth to which the borehole was surveyed
Survey_East_West	Type	Indicates whether survey location is East or West of reference line, such as principal meridian.
Survey_North_South	Type	Indicates whether survey location is North or South of reference line, such as survey baseline.
Survey_Top_Depth	Top_Depth	Shallowest depth of the survey or suite of surveys.
Survey_Type	Type	Type of survey, such as one performed on a Well, e.g., Check Shot or Deviation Survey, or on a Region, Land or Marine, , e.g., Seismic survey.
Synthetic_Seismic_Section	Data_Valued_Property	An artificial seismic section produced by collecting artificially-generated traces (such as a Synthetic_Seismogram from log-derived Reflectivity) or by extracting data from an actual seismic section.
Synthetic_Seismogram	Data_Valued_Property	An artificial seismic reflection record produced by assuming a particular wavelet and model. Commonly, a one dimensional synthetic seismogram is generated by convolving a typical seismic wavelet with log-derived Reflectivity.
Sys_Copy_Number	Sequence_Number	Number used to identify an instance of a particular type object within a set; used in conjunction with Copy_Number in GeoFrame.
System_Identifier	Identifier	Identifier of a computer system.
TBG_Grade_Bearing	Drill_Bit_Grade_TBG	TBG Drill Bit Grade based on bearing condition.
TBG_Grade_Broken_Teeth	Drill_Bit_Grade_TBG	TBG Drill Bit Grade based on broken teeth
TBG_Grade_Gauge	Drill_Bit_Grade_TBG	TBG Drill Bit Grade based on gauge.
TBG_Grade_Gauge_OH	Drill_Bit_Grade_TBG	TBG Drill Bit Grade based on gauge out of hole.
TBG_Grade_Tooth_Grade	Drill_Bit_Grade_TBG	TBG Drill Bit Grade based on teeth condition.
TVD_Computation_Method	Method_Type	Method of defining the wellbore trajectory based upon directional survey data; includes curve fitting to the survey points and extrapolating beyond them.
Table_Name	Name	Name of a database Table.
Tank_Code	Code	Code for the tank
Tank_Type	Type	Tank type
Tape_Density	Data_Valued_Property	Tape density, usually expressed in bits per inch.
Tar_Volume_Fraction	Volume_Fraction	The volume fraction of tar with respect to the total volume.
Tectonic_Cycle_Type	Type	The type of tectonic cycle, i.e. distensive or compressive.
Tectonic_Feature_Type	Type	The type of tectonic environment associated with an Earth subsurface, e.g. Fault, Fold, etc.
Temperature	Data_Valued_Property	The degree of hotness or coldness measured on a definite scale
Temperature_Accuracy	Accuracy	The maximum difference, over the calibrated range, between temperature applied to the gauge, with a reference standard, and the temperature measured by the gauge.
Temperature_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for an temperature measurement.
Temperature_In	Temperature	The temperature of the input material.
Temperature_Measure_Point	Measure_Point_Offset	The distance from the bottom of the Equipment to the point where the Temperature is measured
Temperature_Out	Temperature	The temperature of the output material
Temperature_Sensor_Code	Code	Temperature sensor code
Temperature_Sensor_Resolution	Temperature	The minimum significant temperature change that can be detected above the noise. This is measured as the standard deviation of the differences between two successive measurements.
Temperature_Sensor_Type	Sensor_Type	Type of temperature sensor
Tensile_Yield	Tension	Maximum force which can be applied to an object without causing permanent deformation.
Tension	Force	The force tending to cause extension of a body, as experienced in a cable, rope, string, etc.
Term	Duration	Term of an agreement. Usually in years
Terminal_Mode_Flag	Flag	Flag indicating whether or not the setup was filled in terminal mode (e.g. via an HP hand calculator). This affects the interpretation of the Job_Duration parameter.
Termination_Date	Date	The date on which a lease, an organization, or any legal or organizational entity was terminated.
Test_Code	Code	Catalog-controlled code of test type or analysis method.
Test_Date	Date	The date at which a particular test activity was conducted.
Test_Depth	Depth	Depth at which a formation test is performed; normally taken to be measured depth.
Test_Number	Ordinal_Number	The number (or rank) associated with a particular test activity.
Test_Pressure	Pressure	Recommended pressure at which the equipment is tested when inspected or certified
Tetrahedron_Code	Code	Mineral tetrahedron name, e.g. Pettijohn
Text	Description	Textual body a document or document section, such as a contract clause.
Text_Location	Location	Location of a section of text, such as a contract clause; typical locations are paragraph number or line number on a page.
Theoretical	Modifier	Confined to theory or speculation.
Thermal_Alteration_Index	Indicator	An indicator of the thermal maturity of organic matter, based on a relationship between color of organic particles and the length and intensity of heat exposure.
Thermal_Conductivity	Data_Valued_Property	Heat flux or thermal energy per unit length and temperature. The capacity of a body to conduct or pass thermal energy. The capacity of a material to conduct or pass thermal energy.
Thermal_Gradient	Gradient	The rate of change of temperature with length.
Thermal_Neutron_Decay_Time	Time	The time for the neutron population to fall to 1/e (37%) of its original value. Commonly called Tau, it is inversely related to Neutron_Capture_Cross_Section
Thermal_Neutron_Near_Far_Ratio	Ratio	Ratio of the count rate of the near detector to that of the far detector in a thermal neutron logging device
Thermal_Neutron_Porosity	Neutron_Porosity	Porosity as measured with a thermal neutron logging device.
Theta_Angle	Plane_Angle	The horizontal angle measured counterclockwise from the x-axis.
Thickness	Length	The smallest of three dimensions {length, width, and thickness}
Thickness_Loss	Thickness	Loss of thickness due to any action such as corrosion or erosion
Thin_Out_Azimuth	Azimuth	Azimuth of the thin out of a barrier type depositional environment.
Third_Party_Certification	Data_Valued_Property	Certification by third party for the sampling bottle
Thomsen_Delta	Anisotropy	Thomsen's delta anisotropy parameter, describing the relationship between vertical and moveout Compressional velocities.
Thomsen_Epsilon	Anisotropy	Thomsen's epsilon anisotropy parameter, describing the relationship between vertical and horizontal Compressional velocities.
Thomsen_Gamma	Anisotropy	Thomsen's gamma anisotropy parameter, describing the relationship between Horizontally polarized Shear (SH) velocities in the vertical and horizontal directions.
Thomsen_Sigma	Anisotropy	Thomsen's sigma anisotropy parameter, describing the relationship between Vertically polarized Shear (SV) velocities in the vertical direction and moveout SV velocity.
Thorium_Concentration	Concentration	Concentration of Thorium by weight
Thorium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of thorium to total dry weight
Thorium_Potassium_Ratio	Ratio	Ratio of concentration of Thorium to that of Potassium.
Thorium_Uranium_Ratio	Ratio	Ratio of concentration of Thorium to that of Uranium.
Thorium_Yield	Elemental_Yield	Elemental contribution of Thorium with respect to total.
Thread_Type	Type	Type of thread for casing pipe (such as short, long, buttress, extreme line)
Threshold	Multi_Use_Property	The value of a property which signals some change in state or behavior of a material, process or algorithm.
Threshold_Ratio	Ratio	Relative measure of trace value attribute; ratio of number of samples with values greater than threshold to total number of samples.
Throughput	Data_Valued_Property	A measure of the mass produced, say from some facility, per unit time.
Tie_Point_Phase_Shift	Phase_Shift	Phase difference between traces of seismic lines at a tie point.
Tie_Point_Time_Quality	Correlation_Coefficient	Measure of the significance of a mis-tie computed on a correlation basis.
Tie_Point_Total_Time_Correction	Time_Interval	Total amount of mis-tie correction to apply. Evaluated at line ties.
Time	Data_Valued_Property	1) The measured or measurable period during which an action, process, or condition exists or continues. 2) The point or period when something occurs. 3) A fixed moment or hour for something to happen, begin, or end. 4) A historical period.
Time_After_Bit	Delay_Time	In MWD/LWD logging, the time delay between the drill bit and a sensor reaching a given point in the wellbore.
Time_Dip	Dip_Angle	Dip computed on a time surface by measuring the difference in seismic times between two points compared to the horizontal distance between the points.
Time_Increment	Time_Interval	Time increment between samples indexed by time.
Time_Interpretation	Two_Way_Time	Generic interpretation on seismic traveltime sections
Time_Interval	Time	A time value which is intended to indicate the duration of a process or event.
Time_Of_First_Data	Time_Interval	Listening time until first detection
Time_Pick	Transit_Time	Acoustic transit time (normally a two-way time) from seismic reference datum to the well marker, as picked from a seismic section.
Time_Stamp	Absolute_Time	A time value which is associated with some event to fix its occurrence in time; often expressed as an elapsed time from recent reference time.
Time_System_Offset_Wrt_Standard_Time	Time_Interval	Time zone correction (defined to fractions of an hour) to be added to vehicle system time to correct to standard time. (GMT, UTC,...)
Time_Uncertainty	Uncertainty	Uncertainty of a time measurement.
Time_Unit	Unit_Code	Unit for Time data
Titanium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of titanium to total dry weight
Titanium_Yield	Elemental_Yield	Elemental contribution of Titanium with respect to total.
Title	Name	A formal descriptive name, such as for a publication; also used for the role of person in an organization.
To_Conn_Number	Identifier	Indicates which end or connection number (1 or 2 for tubulars, 3 for a hydraulic T,...) of the "To" equipment in a From_To equipment connection. The description of the "To" connection number is needed in some cases for equipment item which is last in the connection chain. When no ambiguity exists, the From_Conn_Number is the preferred property.
To_Datum_Code	Geodetic_Datum_Code	Code of the target datum used in a datum-to-datum coordinate system transformation (datum shift).
To_Entity_Code	Entity_Code	Code of Entity to which the relationship points
To_Property_Code	Property_Code	Code of Property of Entity to which the relationship points
Tolerance	Statistical_Property	Allowable uncertainty or deviation from a standard; the unit quantity is determined by that of the data value.
Tool_Azimuth	Azimuth	Angle measured clockwise from North to the horizontal projection of the radius passing through the tool angle reference point. One of Tool_Azimuth or Relative_Bearing must be present
Tool_Deviation	Deviation	Angle between the tool axis and the vertical.
Tool_Measure_Point_Offset	Measure_Point_Offset	Distance from the Measure Point to the Tool Reference Plane (most often the bottom tool make-up plane); a positive value indicates that the Measure Point is above the Reference Plane. [Traditionally stored in Parameter MPOI on LIS/DLIS tapes.]
Tool_Number	Identifier	Acquisition system tool number
Tool_Rotation_Speed	Angular_Velocity	Rotational speed of the logging tool
Tool_Speed	Velocity	Speed of the tool; logging speed.
Tool_Status	Status	Indicator of some condition in the operation of a tool.
Tool_String_Measure_Point_Offset	Measure_Point_Offset	Distance from the Measure Point to the Tool String (not just Tool!) Reference Plane; a positive value indicates that the Measure Point is above the Reference Plane. [Traditionally referred to as "tool zero".]
Tool_Temperature	Temperature	Internal temperature of the logging tool
Tool_Type	Type	The type of a Tool usually used in some activity, e.g. CNTA, USIT, AIT, etc.
Toolface	Plane_Angle	In directional drilling, the angle between a reference direction on the drill string and a fixed reference, measured in a plane normal to the drillstring. In near-vertical applications, North is the fixed reference (Magnetic_Toolface); for higher deviation applications, Top of Hole is the reference (Gravity_Toolface).
Toolface_Data_Density	MWD_Data_Density	Density of data samples per length of borehole traversed, for a toolface measurement.
Toolface_Time_After_Bit	Time_After_Bit	In MWD/LWD logging, the time delay between the drill bit and the point at which the toolface measurement is taken reaching a given point in the wellbore.
Top_Charge_Offset	Length	Distance from the bottom (make-up plane) of the gun or the assembly of guns to the upper perforating charge
Top_Depth	Depth	The top depth of a borehole interval, a formation or any depth indexed representation of an data item.
Top_Dip_Number	Dip_Number	Number of Dip (in the Dip Set) at the top of the Bed
Top_Discontinuity_Type	Discontinuity_Type	Type of Discontinuity forming the top boundary
Top_Location	Location	The location of the top of any Entity with a geometric extent (e.g., Zone Interval, Borehole, Borehole Segment, Rig, Arc, Edge, etc.). It is represented by some position relative to a coordinate system.
Top_Subsea_Vertical_Depth	Subsea_Vertical_Depth	Subsea Vertical Depth of Top of Interval
Top_True_Stratigraphic_Thickness_Depth	True_Stratigraphic_Thickness_Depth	True Stratigraphic Thickness Depth of Top of Interval
Top_True_Vertical_Depth	True_Vertical_Depth	True Vertical Depth of Top of Interval
Top_True_Vertical_Thickness_Depth	True_Vertical_Thickness_Depth	True Vertical Thickness Depth of Top of Interval
Top_Two_Way_Time	Two_Way_Time	Depth of Top of Interval in Two Way Time
Top_Value	Multi_Use_Property	Value at the top of an interval.
Top_Vertical_Section	Vertical_Section	Top "depth" of an interval along a Vertical Section (VSCT) index.
Torque	Data_Valued_Property	Something that produces rotation or torsion and whose effectiveness is measured by the product of the force and the perpendicular distance from the line of action of the force to the axis of rotation.
Torsional_Yield	Torque	Maximum torque which can be applied to an object without causing permanent deformation.
Tortuosity	Shape	A characteristic of permeable media that is the squared ratio of the mean flow path length to the medium length.
Total	Modifier	Comprising or constituting a whole.
Total_Compressibility	Compressibility	Compressibility of the rock matrix combined with fluid compressibilities within the matrix.
Total_Depth	Depth	The total depth, usually of the well borehole.
Total_Depth_Date	Date	The date/time at which the drilling reached total depth.
Total_Flow_Area	Surface_Area	Total cross-sectional area through which fluid can flow.
Total_Flowrate	Flowrate	Sum of the flowrates coming from different sources
Total_Formation_Volume_Factor	Formation_Volume_Factor	Ratio of fluid volume (liquid + total solution gas) at specified (typically, reservoir) conditions to the volume of liquid and residual solution gas at surface (stock tank) conditions. Used for two-phase systems; abbreviated Bt; typical range 1.1 - 200.
Total_Geometric_Spreading	Coefficient	The total effect of geometric spreading along ray. Factor giving the reduction in seismic amplitude (<1) due to spreading of the wave between two points. Includes both spherical divergence and cylindrical divergence.
Total_Hardness	Chemical_Concentration	Sum of Ca and Mg concentration in water, API RP13B, Section 8, Water Based Mud, expressed as being entirely composed of calcium
Total_Organic_Carbon	Volume_Fraction	Volume concentration of organic carbon relative to the total volume.
Total_Organic_Matter	Volume_Fraction	Relative content of organic matter in a material, such as a rock sample. Calculated as total organic Carbon * 1.22.
Total_Permeability_Thickness	Permeability_Thickness	Total permeability-thickness [= kh(1) + kh(2)] for a vertical interference test
Total_Porosity	Porosity	The total volume fraction of a rock which is occupied by fluid; includes all forms of porosity, including that occupied by bound fluids, and is independent of rock and fluid materials and of environmental effects
Total_Skin	Skin_Factor	The sum of all formation, completion, deviation, geometric and fluid flow skin factors. It can be a function of the flowrate if a Non-Darcy skin effect is present.
Total_Storativity_Thickness	Storativity_Thickness	Sum of the Storativity_Thickness values of all layers in the model.
Township_Number	Identifier	Jeffersonian Township Number
Trace_Aperture	Width	The size of the aperture of the trace on the borehole surface
Trace_Azimuth	Azimuth	The Azimuth coordinate of a trace
Trace_Count_Receiver	Count	The maximum number of traces which were recorded at any individual receiver for all source events
Trace_Count_Source	Count	The maximum number of traces assigned to the source
Trace_Depth	Depth	The depth coordinate of a trace
Trace_Elements	Description	Description of the trace elements in a sample or material.
Trace_Length	Length	Length of a trace or mark which is visible on some surface, such as that of a road on a map, or of a fracture on a borehole wall.
Tracking_Depth_Operator_Length	Tracking_Operator_Length	Length of the cross correlation window to use while tracking
Tracking_Depth_Window_Bottom	Tracking_Window_Bottom	Distance below the picked Z to search for the Event_Type and Snap_Type while tracking
Tracking_Depth_Window_Top	Tracking_Window_Top	Distance above the picked Z to search for the Tracking Event and Snap_Type while tracking
Tracking_Operator_Length	Time_Interval	Length (time or depth interval) of the crosscorrelation window to use while tracking
Tracking_Quality	Quality_Indicator	The acceptable value of the crosscorrelation for continued tracking (0.0 - 1.0).
Tracking_Window_Bottom	Offset	Interval (time or depth) below the picked Z to search for the Tracking Event and Snap_Type while tracking
Tracking_Window_Top	Offset	Interval (time or depth) above the picked Z to search for the Tracking Event and Snap_Type while tracking
Trade_Name	Name	An arbitrarily adopted name that is given by a manufacturer or merchant to an article or service to distinguish it as produced or sold by him and that may be used and protected as a trademark.
Trajectory	Data_Valued_Property	A description of the path that some activity or object makes as it traverses a medium.
Transfer_Duration	Time_Interval	Duration of sampling operation
Transfer_Fluid_Type	Fluid_Type	Liquid displaced away during sampling
Transient_End_Time	End_Time	End time (tend) of the Transient
Transient_Final_Flowrate	Flowrate	Flowrate at Transient End Time (qend)
Transient_Final_Pressure	Pressure	Pressure at Transient End Time (pend)
Transient_Initial_Flowrate	Flowrate	Flowrate at start of Transient
Transient_Initial_Pressure	Pressure	Pressure at start of Transient
Transient_Start_Time	Start_Time	Start time (t0) of the Transient
Transit_Time	Time_Interval	Time required for a wave to travel from one point to another.
Transit_Time_Accuracy	Accuracy	The accuracy attached to the transit time measurement or computation.
Transit_Time_Ampmod	Transit_Time	Transit time estimated from processing
Transit_Time_Initial	Transit_Time	Initial transit time
Transit_Time_NMO	Transit_Time	Normal moveout transit time
Transit_Time_Nominal	Transit_Time	Nominal transit time
Transit_Time_Qfactor	Transit_Time	Transit time q-factor
Transit_Time_SRD	Transit_Time	Transit time with respect to seismic reference datum
Transit_Time_Sensor	Transit_Time	Transit time taken from tool sensor
Transit_Time_Shear	Transit_Time	Shear wave transit time
Transit_Time_Slope	Transit_Time	Transit time slope
Transmission_Coefficient	Ratio	Ratio of the amplitude of a transmitted wave to that of the incident wave; may be greater than 1.
Transverse_Amplitude	Amplitude	Amplitude of transverse component in multi-component seismic.
Transverse_Dispersivity_Coefficient	Coefficient	The coefficient used as a multiplier of interstitial velocity to estimate dispersion normal to the direction of movement for a displacement front.
Transverse_Isotropy_Coefficient	Coefficient	The degree of transverse isotropy in a medium; that is, having the different property values when measured within or normal to a plane. Usually represented by the 5 coefficients of the Stiffness matrix: C11, C13, C33, C44, C66.
Transverse_Relaxation_Time	Relaxation_Time	Transverse, or spin-spin, relaxation time constant for transverse magnetization decay rate of nuclei; normally abbreviated by symbol T2.
Treatment_Bottom_Depth	Depth	Depth of the borehole at the moment of the treatment
Treatment_Displacement_Volume	Volume	Dead volume including the surface treating lines to be pumped to move the treating fluid down to formation. In cementing it is the volume (through casing/tubing/ drillpipe) up to the landing collar; in acidizing it is the tubing volume to perforations
Treatment_Flow_Path	Type	Indicates how the fluid is pumped into the well e.g. by the casing, the tubing, the annulus Casing-tubing ...
Treatment_Number	Identifier	Internal Dowell treatment number
Treatment_Rate	Flowrate	Total flowrate pumped downhole in a well treatment activity
Trimmed_Length	Length	Length of material which has been cut away either to prevent fatigue rupture on a cable or a coiled tubing or to connect an equipment
Trona_Volume_Fraction	Volume_Fraction	The volume fraction of trona with respect to the total volume.
Trough_Peak_Amplitude_Ratio	Ratio	Ratio of amplitudes of peak and trough.
Trough_Peak_Delta_Amplitude	Amplitude	Amplitude difference between trough and peak.
Trough_Peak_Delta_Depth	Thickness	Depth difference between trough and peak where trough occurs first in increasing depth
Trough_Peak_Delta_Time	Time_Interval	Time difference between trough and peak
Trough_Trough_Amplitude_Ratio	Ratio	Ratio of amplitudes of two troughs.
Trough_Trough_Delta_Amplitude	Amplitude	Amplitude difference between two troughs.
Trough_Trough_Delta_Depth	Thickness	Depth difference between successive troughs
Trough_Trough_Delta_Time	Time_Interval	Time difference between two troughs
True	Modifier	Conformable to an essential reality. In Earth science, determined with reference to the earth axis rather than the magnetic poles.
True_Common_Depthpoint_Number	Ordinal_Number	CDP Line Number
True_Common_Depthpoint_Offset	Offset	Shot position relative to the CDP Line
True_Common_Midpoint_Position	Rectangular_Position	Common midpoint (CMP) position
True_Common_Midpoint_X_Coord	X_Coordinate	X-coordinate of Common midpoint (CMP) position
True_Common_Midpoint_Y_Coord	Y_Coordinate	Y-coordinate of Common midpoint (CMP) position
True_Common_Midpoint_Z_Coord	Z_Coordinate	Z-coordinate of Common midpoint (CMP) position
True_Receiver_Line_Position	Receiver_Line_Position	True position in a receiver line
True_Receiver_Line_Position_Rho	Receiver_Line_Rho	Horizontal (x-y) distance from origin of true position in a receiver line.
True_Receiver_Line_Position_Theta	Receiver_Line_Theta	Horizontal angle of true position in a receiver line, measured counter-clockwise from x-axis.
True_Receiver_Line_Position_Z	Receiver_Line_Z	Z-coordinate of true position in a receiver line.
True_Receiver_Position	Rectangular_Position	True receiver position
True_Receiver_Position_X_Coord	X_Coordinate	X-coordinate of true receiver position.
True_Receiver_Position_Y_Coord	Y_Coordinate	Y-coordinate of true receiver position.
True_Receiver_Position_Z_Coord	Z_Coordinate	Z-coordinate of true receiver position.
True_Scale_Latitude	Latitude	Latitude at which scale is true, as with a standard parallel.
True_Source_Line_Position	Source_Line_Position	True position in a source line.
True_Source_Line_Position_Rho	Source_Line_Rho	Horizontal (x-y) distance from origin of true position in a source line.
True_Source_Line_Position_Theta	Source_Line_Theta	Horizontal angle of true position in a source line, measured counter-clockwise from x-axis.
True_Source_Line_Position_Z	Source_Line_Z	Z-coordinate of true position in a source line.
True_Source_Position	Rectangular_Position	True source position
True_Source_Position_X_Coord	X_Coordinate	X-coordinate of true source position.
True_Source_Position_Y_Coord	Y_Coordinate	Y-coordinate of true source position.
True_Source_Position_Z_Coord	Z_Coordinate	Z-coordinate of true source position.
True_Source_Sensor_Position	Rectangular_Position	Position of sensor placed near source, for detection of shot event.
True_Source_Sensor_Position_X_Coord	X_Coordinate	X-coordinate of position of sensor placed near source, for detection of shot event.
True_Source_Sensor_Position_Y_Coord	Y_Coordinate	Y-coordinate of position of sensor placed near source, for detection of shot event.
True_Source_Sensor_Position_Z_Coord	Z_Coordinate	Z-coordinate of position of sensor placed near source, for detection of shot event.
True_Stratigraphic_Thickness	Thickness	Cumulative thickness of an earth layer, measured perpendicular to the bedding plane, thus eliminating any offset effect due to borehole deviation or structural dip. Also called True Bed Thickness.
True_Stratigraphic_Thickness_Depth	Depth	The depth of a point relative to a True Stratigraphic Thickness (TST) Index. Such indices may be local to a particular zone interval, hence their values can only be compared to other values referenced to the same index.
True_Vertical_Depth	Depth	The true vertical depth from the surface of the Earth to a particular subsurface point.
True_Vertical_Thickness	Thickness	Isochores obtained by correcting for structural dip in order to account for the lateral offset of the intersections of the well bore with the top and bottom of a layer.
True_Vertical_Thickness_Depth	Depth	The depth of a point relative to a True Vertical Thickness (TVT) Index. Such indices may be local to a particular zone interval, hence their values can only be compared to other values referenced to the same index.
Tube_Drift_Diameter	Drift_Diameter	Drift diameter of tube or body of equipment item.
Tube_Material	Material_Code	Material composition of the tubular product.
Tube_Nom_Inside_Diameter	Nom_Inside_Diameter	Nominal inside diameter of body or actual inside diameter tube (for API spec. drill pipe)
Tube_Nom_Length	Nom_Length	Nominal length of tube of body of equipment item.
Tube_Nom_Outside_Diameter	Nom_Outside_Diameter	Nominal outside diameter of body or API nominal outside diameter of tube
Tube_Tensile_Yield	Tensile_Yield	Maximum Force which can be applied to a tube or body without causing permanent deformation.
Tube_Torsional_Yield	Torsional_Yield	Maximum torque which can be applied to the tube or body without causing permanent deformation.
Tube_Upset_Type	Type	Type of upset in tube or body
Tube_Wall_Thickness	Thickness	Wall thickness of tube or body of equipment item.
Tubing_Shoe_Depth	Depth	Tubing shoe depth
Tubular_Code	Code	Specific code of the tubular goods.
Tubular_String_Component_Rank	Rank	A rank denoting the order of the element in a string of tubular drilling equipment.
Tubular_String_Connect_Type	Type	The string tubular equipment connection number that is at the top. Allowed values are: UNKNOWN, 1st connection, and 2nd connection.
Tubular_String_Location_Type	Type	The location of the super tubular equipment where the sub tubular equipment is attached. Allowed values are: UNKNOWN, attached outside of super string equipment, and attached inside of super string equipment
Tubular_String_Offset	Length	The distance from the mid-point of the sub tubular equipment to the bottom of the super tubular equipment where the sub tubular equipment is attached.
Tubular_Type	Type	The type of a Tubular used in some activity or installed in and part of the well structure, e.g. Casing, Production Tubing, etc.
Turbulence_Coefficient	Indicator	The coefficient that describes the additional pressure drop due to inertial effects for high velocity gas flow.
Two_Way_Time	Acoustic_Travel_Time	The time required for an acoustic wave to travel from its source to a reflector and return to a receiver.
Type	Data_Valued_Property	The type of any item. Applies to all items in all domains.
UNKNOWN	Property	Unknown property type; used to assert that a specific Property Code cannot be determined from the information provided.
URL	Address	Address of Worldwide Web site; acronym for Universal Resource Locator
UWI	Identifier	The unique Identifier given to a well or a borehole specified in a given naming system. This identifier can be granted by either an official regulatory commission such as the API 12/14 digits, the Canadian Petroleum Association (CPA) or by any organization (user, customer), described in Well.Naming_System.
Ultrasonic_Caliper	Caliper	Borehole diameter as measured by an ultrasonic logging device.
Uncertainty	Statistical_Property	Precision with which a measurement is known; often implies a 50-50 chance that any one of a series of measurements will fall within a given range; the unit quantity is determined by that of data value. Uncertainty is not necessarily related to Accuracy.
Uncertainty_Radius	Uncertainty	Magnitude of uncertainty for a measurement being represented as a position in 2D or 3D coordinate space, such as a geographical position.
Unconformity_Type	Type	The type of an unconformity in the Earth subsurface, e.g. Joint, Disconformity, Diastem, etc.
Undisturbed_Zone_Bound_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of bound water in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Dissolved_Salt_Volume_Fraction	Volume_Fraction	The volume fraction of dissolved salt in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Free_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of free water in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Gas_Volume_Fraction	Gas_Volume_Fraction	The volume fraction of gas in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Hydrocarbon_Volume_Fraction	Hydrocarbon_Volume_Fraction	The volume fraction of hydrocarbon in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Irreducible_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of irreducible water in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Oil_Volume_Fraction	Oil_Volume_Fraction	The volume fraction of oil in the undisturbed zone with respect to the total volume.
Undisturbed_Zone_Water_Volume_Fraction	Water_Volume_Fraction	The volume fraction of water in the undisturbed zone with respect to the total volume.
Unit_Attribute	Attribute_Name	Name of Object Attribute where Unit may be found if not otherwise specified
Unit_Canonical_Form	Unit_Code	Canonical form of defining unit for this Dimension
Unit_Code	Code	Code of a Unit Symbol in the SDM/OSDD Units model or of an RP66 Unit expression.
Unit_Column	Column_Name	Database column name where Unit may be found if not otherwise indicated.
Unit_Cost	Cost	Cost per unit amount
Unit_Dimension_Code	Code	Code of a Unit Dimension in the SDM/OSDD Units model
Unit_Namespace_Code	Namespace_Code	Code of the Namespace for a Unit Symbol
Unit_Object	Object_Name	Name of Object where Unit may be found if not specified
Unit_Quantity_Code	Code	Code of a Unit Quantity in the SDM/OSDD Units model
Unit_Quantity_Column	Column_Name	Name of column in database table where Unit may be found if not otherwise indicated.
Unit_Quantity_Table	Table_Name	Name of database table where Unit may be found if not otherwise indicated.
Unit_System_Code	Code	Code of a Unit System in the SDM/OSDD Units model.
Unit_Table	Table_Name	Name of database table where Unit may be found if not otherwise indicated.
Up_Load	Load	Upward load exerted on an equipment item.
Up_Stroke	Stroke_Length	Up stroke distance, as used for drilling jars. Maximum stroke travel in shock/cushion sub
Upper_Fluid_Type	Fluid_Type	The type of fluid found in the layer above a reference surface (e.g. Water in layer above a Fluid Contact in a Reservoir,)
Upper_Surface_Relation	Type	The type of relationship between a surface and the ones above (e.g. the surfaces below a Horizon are onlapping.)
Upset_Diameter	Diameter	Upset diameter (such as replaceable sleeve stabilizer)
Upstream_Coil_Pressure	Pressure	Coil working pressure upstream of the choke box
Uranium_Concentration	Concentration	Concentration of Uranium by weight
Uranium_Dry_Weight_Fraction	Dry_Weight_Fraction	Ratio of dry weight of uranium to total dry weight
Uranium_Potassium_Ratio	Ratio	Ratio of concentration of Uranium to that of Potassium.
Uranium_Yield	Elemental_Yield	Elemental contribution of Uranium with respect to total.
Use_Checkshot_Flag	Flag	A processing option indicating whether or not Checkshot survey data should be used for depth-time conversion.
User_Data_Ident	Data_Mask	User-defined mask
User_Evaluation_Code	Data_Mask	Auxiliary user-defined mask
User_Trace_Selection	Flag	Good/bad marker
Validation_Flag	Flag	Flag indicating that validation will be or has been performed on the data.
Value_Domain_Code	Code	Code of an SDM Value Domain
Value_Long	Multi_Use_Property	Value if of data type Long
Value_Number	Multi_Use_Property	Value if of data type Number
Value_String	Multi_Use_Property	Value if of data type String
Value_Type	Code	Code of value type of data
Value_Type_Code	Code	Code of value type of data
Value_Type_Column	Column_Name	Name of column in database table where value type may be found if not otherwise indicated.
Value_Type_Table	Table_Name	Name of database table where value type may be found if not otherwise indicated.
Valve_Inside_Diameter	Inside_Diameter	Inside diameter of the valve assembly
Variable_Deck_Load	Load	Current temporary load on the rig deck
Variance	Statistical_Property	A measure of the width of the probability distribution for a single random variable; the square of standard deviation.
Velocity	Data_Valued_Property	The rate of change of the displacement of a body in time.
Velocity_Alpha_Factor	Gradient	Gradient factor a for Faust 6th root velocity function v(z) = a * z**(1/6)
Velocity_At_Z0	Acoustic_Velocity	(Instantaneous) Velocity at surface reference z=0 (z is time or depth).
Velocity_Beta_Factor	Gradient	Gradient factor b for Faust 3rd root velocity function. v(z) = b * z**(1/3)
Velocity_Ellipticity_Azimuth	Azimuth	Fastest direction of elliptic anisotropic velocity (i.e. ellipse major axis) measured clockwise from grid north in degrees.
Velocity_Ellipticity_Flattening	Ratio	Degree of velocity elliptical anisotropy, in the range 0 (isotropic) to 1, defined as the ratio of the difference between the major and minor axes to the major axis of the velocity ellipse.
Velocity_Gamma_Factor	Gradient	Gradient factor g for Faust Nth root velocity function v(z) = g * z**(1/n)
Velocity_Gradient_In_Depth	Gradient	First derivative of velocity versus depth
Velocity_Gradient_In_Time	Gradient	First derivative of velocity versus time.
Velocity_K_Factor	Gradient	Velocity depth gradient, dv/dz used in some velocity functions like linear velocity : v(z) = v_0 + kz depth of burial : v(z,z_1) = v_0 + k_1z_1 + k_2*(z-z_1)
Velocity_To_Seismic_Datum	Acoustic_Velocity	Velocity of the medium between the zero-time reference of a particular survey to the Seismic Reference Datum.
Velocity_Uncertainty	Uncertainty	Uncertainty of a velocity measurement.
Version	Identifier	Software version number
Vert_Hor_Permeability_Ratio	Vert_Hor_Ratio	The ratio of vertical to horizontal permeability in a permeable medium.
Vert_Hor_Ratio	Ratio	The ratio of some property measured vertically to that of the same property measured horizontally; several such property types are used to characterize formation anisotropy.
Vertical_Datum_Code	Code	Code of the permanent Vertical Datum to which the local elevation reference is related. Typical Vertical Datums are "MSL" and "GL".
Vertical_Datum_Name	Name	Name of the permanent Vertical Datum to which the local elevation reference is related. Typical Vertical Datums are "Mean Sea Level" and "Least Astronomic Tide".
Vertical_Depth_Offset	Depth_Offset	Offset in true vertical depth versus some true vertical depth reference.
Vertical_Formation_Resistivity	Formation_Resistivity	Formation resistivity measured perpendicular to layering. (for "Transverse-Isotropic (TI)" rock
Vertical_Geometric_Skin	Skin_Factor	In a horizontal well, skin effect due to the limited entry in the vertical direction.
Vertical_Lift_Depth	Depth	Tubing depth in vertical lift fluid flow computation
Vertical_Lift_Flow_Regime_Flag	Flag	Flag identifying flow regime flag at some depth
Vertical_Lift_Pressure	Pressure	Computed pressure at some depth in tubing
Vertical_Lift_Temperature	Temperature	Computed temperature at some depth in tubing
Vertical_Mean_Permeability	Geometric_Mean_Permeability	Geometric mean permeability in the vertical plane (Y-Z) of the reservoir
Vertical_Mobility	Mobility	A measure of the ease with which a fluid can be moved vertically in a specific medium (i.e. rock). The ratio of the effective vertical permeability and the viscosity of the fluid.
Vertical_Permeability	Directional_Permeability	A permeability oriented vertically perpendicular to the bedding plane of the stratum. Usually abbreviated as Ky.
Vertical_Rotation	Inclination	Vertical inclination of the ellipses of uncertainties relative to the wellbore at the associated survey point.
Vertical_Section	Length	Vertical Section, historical name given to the horizontal distance from the surface location to the downhole point (horizontal counterpart to True Vertical Depth).
Vertical_Section_Azimuth	Azimuth	Angle between the true north and the vertical section plane.
Vertical_Section_Origin	Location	The location and orientation of the vertical section plane in which vertical section distances are measured.
Vertical_Size	Height	The size of any object as measured vertically
Vertical_Time_Thickness	Time_Interval	Vertical time difference between layers.
Viscosibility	Data_Valued_Property	Normalized derivative of viscosity: -(dv/dp)/v where v=viscosity and p=pressure.
Viscosity	Data_Valued_Property	The property of a substance offering internal resistance to flow; a measure of the degree of fluidity.
Visibility	Length	Maximum distance at which objects can still be discerned or identified visually.
Visible_Width	Width	For core images, the width of the core which is visible in the image.
Vitrinite_Reflectance	Data_Valued_Property	The optical reflectivity of solid organic constituents of rock, known as vitrinite, which provides an indication of thermal maturity.
Volume	Data_Valued_Property	A measure of the space occupied by a body in cubic units; e.g., cm3, in3, quarts, liters, etc.
Volume_Fraction	Ratio	The ratio of the volumes occupied by two components, or by one component to the total volume of the system.
Volume_Per_Length	Data_Valued_Property	The measure of volume per linear displacement, usually given in bbl/in, bbl/ft, U.S. gal/ft.
Volume_Reflection_Spectrum	Amplitude	Volume Reflection Spectrum, i.e. spectral decomposition of the amplitude response in interval
Volume_Safety_Factor	Safety_Factor	Volume in excess of what has been calculated for the job. Used to account for loss or safety margin
Volume_Type	Type	The type of an Earth subsurface region or volume, e.g. Formation, Reservoir, Tank, Bed, etc.
Volumetric_Coefficient	Data_Valued_Property	Multiplicative factor (Volume per pulse), sometimes called K Factor.
Volumetric_Photoelectric_Factor	Data_Valued_Property	A lithology indicator computed from bulk density and Photoelectric Factor; often expressed in an approximation unit barns/cc.
Von_Mises_Stress	Stress	Normalized sum of the square of the differences of principal stresses applied to a material, e.g. for coiled tubing hoop, bending & radial. See Von_Mises_To_Yield_Ratio.
Von_Mises_To_Yield_Ratio	Ratio	Ratio of the Von_Mises_Stress to the Yield Strength of the material : It helps determine whether the material has yielded (permanently damaged) by comparing to the yield_stress (>1, permanently deformed).
Vsplib_Waveform_Header	Data_Valued_Property	The waveform header used in Vertical Seismic Profile. The structure of the data is specific to Schlumberger Borehole Seismic applications.
Wall_Building_Coefficient	Data_Valued_Property	(Fracturing) Measure of the capability of a fluid flowing in front of a porous media to build up a filter cake inhibiting the fluid leakoff through the porous media. Non RPP66 unit :length/(time)1/2 e.g. ft/min1/2
Warmup_Duration	Duration	Duration between power-on time and acquisition start time.
Washout_Caliper_Diff	Caliper	The degree of a borehole ovality beyond which caliper data becomes unreliable due to bad contact with the tool pads.
Washout_Caliper_Ext	Caliper	The extension of a borehole diameter beyond which caliper data becomes unreliable due to bad contact with the tool pads.
Water_Acoustic_Velocity	Acoustic_Velocity	Sound velocity in water. Typical value under reservoir conditions is 1550 m/s.
Water_Activity	Volume_Fraction	Measure of the water concentration in aqueous solutions expressed as a decimal fraction between 0 and 1 ( = 1 for pure water)
Water_Bubble_Flow_Velocity	Flow_Velocity	Water Bubble Velocity
Water_Compressibility	Compressibility	The compressibility of water at a given pressure and temperature.
Water_Concentration	Volume_Fraction	Water Concentration per fluid Volume
Water_Conductivity	Conductivity	Conductivity of Connate Water (in formation)
Water_Connection_Size	Diameter	Standard water pipe size connection supplied on the equipment inlet
Water_Cut	Volume_Fraction	The percent of water per total volume of liquid over a period of time for a product flow network unit.
Water_Density	Density	The density of water.
Water_Depth	Depth	Water depth
Water_Flow_Velocity	Flow_Velocity	Flow velocity of water component of fluid.
Water_Flowrate	Flowrate	Rate of flow of water
Water_Formation_Volume_Factor	Formation_Volume_Factor	Ratio of water volume at specified (typically, reservoir) conditions to the water volume at surface (stock tank) conditions. Normally abbreviated Bw; typical range .99 - 1.07.
Water_Fraction	Volume_Fraction	Volumetric fraction of water in the total fluid
Water_Gravity	Specific_Gravity	The ratio of the density of the produced or reservoir water to that of pure water at atmospheric conditions
Water_Holdup	Holdup	Volume fraction of water in the upward-moving stream of a producing well.
Water_Mass_Flowrate	Mass_Flowrate	Mass flowrate of water.
Water_Metering_Line_Size	Diameter	Diameter of the water metering line
Water_Neutron_Capture_Cross_Section	Neutron_Capture_Cross_Section	The macroscopic capture cross section, i.e. the effective cross sectional area per unit volume, of water for the capture of neutrons.
Water_Oil_Ratio	Ratio	A measure of the volume of water which is produced with a given quantity of oil.
Water_Rate_Meter_Type	Type	Type of liquid meter used to measure the water rate
Water_Resistivity	Resistivity	Resistivity of connate (formation) water
Water_Salinity	Salinity	Total salts in solution (Na, K, Cl, So4, ..). Normal sea water has around 35,000 ppm (parts per million) salinity. Less than 2,000 ppm is considered "fresh".
Water_Saturation	Saturation	The extent to which the pore space in a formation contains water.
Water_Saturation_At_Breakthrough	Water_Saturation	Water saturation at the breakthough point. In Special Core Analysis, breakthough is the appearance of the injected fluid at the outlet face of the rock sample.
Water_Saturation_At_Breakthrough_FF	Water_Saturation	Water saturation at the breakthough point, calculated from fractional flow curve (SCAL SwBkFF). In Special Core Analysis, breakthough is the appearance of the injected fluid at the outlet face of the rock sample.
Water_Saturation_Min_So_3Phase	Water_Saturation	The water saturation at minimum oil saturation in a three phase system. (SCAL SWM)
Water_Viscosibility	Viscosibility	Normalized derivative of viscosity for water: -(dv/dp)/v where v=viscosity and p=pressure.
Water_Viscosity	Viscosity	The viscosity of water at specific temperature and pressure conditions.
Water_Viscosity_Correlation	Name	Model used to compute water viscosity
Water_Volume_Fraction	Volume_Fraction	The volume fraction of Water with respect to the total volume; the product of Porosity and Water_Saturation
Water_Wettability_Index	Wettability_Index	Relative affinity of a mineral surface for water.
Wave_Azimuth	Azimuth	Azimuth of the direction from which the waves are coming.
Wave_Differential_Energy	Gradient	The change in attenuation of an acoustic wave (compressional, shear or Stoneley) per unit length.
Wave_Height	Height	Average trough-to-peak height of the waves.
Wave_Period	Time_Interval	Average elapsed time between the passing of two wave peaks.
Waveform_Number	Ordinal_Number	Waveform number
Wavelet_Type	Type	Type of wavelet used to deconvolve seismic data or to convolve with a basic reflection model to produce synthetic seismic data.
Wavenumber	Data_Valued_Property	Spatial frequency, reciprocal of wavelength
Weathering_Depth	Depth	Depth of the weathered layer, the near-surface low velocity layer consisting of unconsolidated material and rock in which air rather than water fills the pore space.
Weathering_Depth_CDP	Weathering_Depth	Depth of weathered layer at a CDP.
Weathering_Velocity	Acoustic_Velocity	Average acoustic velocity of the weathered layer, the near-surface low velocity layer consisting of unconsolidated material and rock in which air rather than water fills the pore space.
Weathering_Velocity_CDP	Weathering_Velocity	Weathering velocity at a CDP.
Weight	Force	The force with which a body is attracted toward the center of the earth or any celestial body by gravitation. The product of the mass of the body by the local gravitational acceleration.
Weight_Indicator_Load	Load	Weight indication as measured at the sensor. In a coiled tubing unit, the sensor is located at the base of the injector head.
Weight_On_Bit	Force	The downward force exerted by the drillbit on the formation being drilled.
Weight_Per_Joint	Weight	Weight of each joint in a string of equipment
Weight_Safety_Factor	Safety_Factor	Weight in excess of what has been calculated for the job. Used to account for loss or safety margin
Welded_Section_Flag	Flag	Y/N : does the section has a weld or not : used as a weak point flag in coiled tubing.
Well_Count	Count	The count of the numbers of wells.
Well_Job_Count	Count	Total Number of jobs
Well_Name	Name	Name given to a well, quite possibly the legal name. The name may vary as ownership and rights are transferred.
Well_Production_Control_Mode	Type	Describes what controls the production flow of the well (e.g. constant wellhead pressure, constant flowrate)
Well_Projection_Type	Type	Characterizes the way a well borehole is projected onto a cross section.
Well_Spacing	Reservoir_Distance	Average distance between two wells, connected or not to regulatory petroleum laws
Well_Status	Status	A property indicating the operational condition of a well: proposed, active, abandoned, etc.
Well_Test_Model	Type	Type of well test: e.g. Conventional, Horizontal, Interference, etc.
Well_Test_Model_Type	Type	Type of Well Test Model selected
Well_Test_Type	Type	The type of test conducted on a Well.
Well_Thermal_Gradient	Thermal_Gradient	The rate of change of temperature with measured depth in a well; equivalent to Geothermal_Gradient for a vertical well whose temperature has stabilized.
Well_To_Boundary_Distance	Reservoir_Distance	The distance between the well trajectory and the adjacent reservoir boundary distance.
Well_To_Boundary_Distance_X	X_Coordinate	The distance between the well trajectory and the adjacent reservoir boundary in the X direction.
Well_To_Boundary_Distance_Y	Y_Coordinate	The distance between the well trajectory and the adjacent reservoir boundary in the Y direction.
Well_To_Fault_Angle	Plane_Angle	The angle between the well and either sealing fault in a wedge well test model.
Well_To_Fault_Distance	Reservoir_Distance	The distance between the sealing fault and the well trajectory.
Well_To_Fracture_Element_Distance	Reservoir_Distance	Distance from Borehole to start of fracture element
Well_Treatment_Fluid_Type	Fluid_Type	Type of Fluid used in Well Treatment operation
Well_Treatment_Type	Type	Matrix acidizing, Cementing, Acid fracturing, Hydraulic fracturing, Gravel Packing ...
Wellbore_Purpose	Type	A property indicating the purpose of a wellbore (borehole).
Wellbore_Shape	Shape	Type of wellbore trajectory shape; common types are: build & hold, S shaped, vertical, horizontal. In the early stages of well planning, this information, along with some key parameters, are used to generate an approximate well profile - without the requirement for detailed trajectory planning. This information is also of value for wells that have already been drilled because it is difficult to categorize wells by their detailed trajectory.
Wellbore_Status	Status	A property indicating the operational condition of a wellbore: proposed, active, abandoned, etc.
Wellbore_Storage	Data_Valued_Property	Measure of the ability of the wellbore to store fluid ("afterflow" when a well is shut in) or unload fluid (when a well is opened to flow).
Wellbore_Storage_Type	Type	Describes Wellbore storage behavior as either constant, variable (exp), or variable (erf).
Wellbore_Tortuosity_Amplitude_Angle	Plane_Angle	Amplitude translated as an inclination of the sinusoidal function fitting the survey station points and simulating a real well path
Wellbore_Tortuosity_Wave_Length	Length	The wave length of the sinusoidal function fitting the deviation survey station points and simulating a real well path
Wellhead_Connection_Type	Type	Type of wellhead connection (flange, tree- saver ..); data must identity the mechanical item unambiguously to allow a hydraulic connection e.g. Studded Flange API BX150-15000 psi.
Wellhead_Flowing_Pressure	Pressure	Pressure at the Wellhead with well flowing
Wellhead_Flowing_Temperature	Temperature	Temperature at the Wellhead with well flowing
Wellhead_Gas_Flowrate	Gas_Flowrate	Gas flowrate at the Wellhead
Wellhead_Liquid_Flowrate	Liquid_Flowrate	Liquid flowrate at the Wellhead
Wellhead_Pressure	Pressure	The producing or shutin pressure at the top of the well before any surface pressure drops.
Wellhead_Producing_Gas_Liquid_Ratio	Gas_Liquid_Ratio	Ratio of volume of gas to volume of liquids produced at the wellhead.
Wellhead_Producing_Liquid_Gas_Ratio	Liquid_Gas_Ratio	Ratio of volume of liquids to volume of gas produced at the wellhead; used primarily to express the amount of condensate produced in gas wells; typical unit is barrel per million cubic feet (RP66: 1E-6 bbl/ft3)
Wellhead_Producing_Water_Cut	Producing_Water_Cut	Water Cut at the Wellhead while well is producing
Wellhead_Shutin_Pressure	Pressure	Static wellhead pressure during test
Wellhead_Temperature	Temperature	The temperature at the wellhead occurring at the time of the activity being performed on the well.
Wet_Gas_Critical_Pressure	Critical_Pressure	The pressure needed to condense a wet gas at its critical temperature (Wet gas : mixture of free gas plus condensate)
Wet_Gas_Critical_Temperature	Critical_Temperature	The highest temperature at which the gas can exist as a liquid and above which its vapor cannot be liquefied regardless of the amount of pressure (Wet gas - mixture of free gas plus condensate)
Wet_Gas_Gravity	Gas_Gravity	The ratio of the molecular weight of the wet gas to that of air (Wet gas - mixture of free gas plus condensate)
Wettability_Index	Data_Valued_Property	Relative affinity of a mineral surface for hydrophilic (water wet) or hydrophobic fluids.
Wetting_Contact_Angle	Plane_Angle	Angle between a fluid droplet and a solid surface at the point of contact; the lower the angle (measured inside the droplet), the greater the adhesion and thus the greater the wettability of the solid to that fluid.
Wetting_Type	Type	Classification of the wetting characteristic of the rock, such as Oil Wet or Water Wet.
Wheel_Circumference	Length	Wheel Circumference
Width	Length	The measurement taken at right angles to the length.
Wind_Azimuth	Azimuth	Azimuth of the direction from which the wind is blowing.
Wind_Velocity	Velocity	Velocity of the wind
Windchill_Temperature	Temperature	A measure of the combined chilling effect of wind and low temperature on living things, also named chill factor, e.g., according to US weather service table, an air temperature of 30 degF with a 10 mi/h corresponds to a "wind-chill" of 22 degF.
Window_End_Time	End_Time	End time of the processing window.
Window_Start_Time	Start_Time	Start time of the processing window.
Wire_Diameter	Outside_Diameter	Diameter of wire, such as that used in a mesh or a slotted liner
Wireline_Tool_Type	Tool_Type	The type of a Tool usually used in some wireline activity, e.g. CNTA, USIT, AIT, etc.
Working_Pressure	Pressure	Pressure at which an equipment item normally operates
Working_Temperature	Temperature	Temperature at which an equipment item normally operates
X_Acceleration	Acceleration	Acceleration along the X-axis.
X_Coordinate	Coordinate	X-coordinate of Location
X_Direction_Permeability	Directional_Permeability	Permeability in X Direction
X_Displacement	Displacement	Displacement in the X Direction relative to some coordinate system; e.g., the X-Component of the Well departure from the vertical.
X_Display_Identifier	System_Identifier	XServer Id on which application is to display output
X_Magnetometer	Magnetic_Field_Strength	Magnetic Field Strength along the X-axis.
X_Transverse_Amplitude	Amplitude	X component of Transverse_Amplitude in multi-component seismic.
Y_Acceleration	Acceleration	Acceleration along the Y-axis.
Y_Coordinate	Coordinate	Y-coordinate of Location
Y_Direction_Permeability	Directional_Permeability	Permeability in Y Direction
Y_Displacement	Displacement	Displacement in the Y Direction relative to some coordinate system; e.g., the Y-Component of the Well departure from the vertical.
Y_Magnetometer	Magnetic_Field_Strength	Magnetic Field Strength along the Y-axis.
Y_Transverse_Amplitude	Amplitude	Y component of Transverse_Amplitude in multi-component seismic.
Yield_Strength	Pressure	Unit stress which will produce a small amount of deformation generally equal to a strain of 0.2%. This value is a little greater than the Elastic limit. It is often supplied by the manufacturer of the material.
Yield_Stress	Shear_Stress	Resistance to initial flow; the stress required to start fluid movement. Specifically, shear stress at 0 shear rate for Bingham Plastic (BP) rheological model, otherwise named Bingham yield value or yield point. BP fluid remains static until applied forces build up to the point where it starts to move. See Plastic_Viscosity.
Young_Modulus	Elastic_Modulus	The stress-strain ratio when a body is pulled or compressed.
Z_Acceleration	Acceleration	Acceleration along the Z-axis.
Z_Coordinate	Coordinate	Z-coordinate of Location
Z_Factor	Coefficient	The factor which corrects for the deviation of a gas from the ideal gas law when calculating PVT relationships.
Z_Gravity	Gravity	Strength of the z-axis component of the gravitational field at some location; used to correct total z-axis acceleration of a logging tool to compute actual tool movement.
Z_Magnetometer	Magnetic_Field_Strength	Magnetic Field Strength along the Z-axis.
Z_Transverse_Amplitude	Amplitude	Z component of Transverse_Amplitude in multi-component seismic.
Zenith_Angle	Plane_Angle	Angle from an upward-pointing vertical line, measured in a vertical plane. A horizontal line has a zenith angle of 90 degrees
Zero_Crossing_Count	Count	Count of zero crossings of waveform(s).
Zinc_Yield	Elemental_Yield	Elemental contribution of Zinc with respect to total.
Zirconium_Yield	Elemental_Yield	Elemental contribution of Zirconium with respect to total.
Zone_Length	Interval_Length	The length of a zone, usually along the borehole.
Zone_Name	Name	Zone Name
Zone_Number	Ordinal_Number	An ordinal identifier that uniquely characterizes each zone
Zone_Set_Type	Type	The type of a set of zone intervals traversing one or more Boreholes and/or one or more Earth subsurface Volumes.
Zone_Start	Depth	The start depth of a zone, usually along the borehole. This may be the deeper or the shallower end of the zone.
Zone_Stop	Depth	The stop depth of a zone, usually along the borehole. This may be the deeper or the shallower end of the zone.
i_C4H10_Concentration	Chemical_Concentration	Concentration of iso-Butane (i-C4H10); typical volume concentration in natural gas is 0.3%.
i_C5H12_Concentration	Chemical_Concentration	Concentration of iso-Pentane (i-C5H12); typical volume concentration in natural gas is 0.3%.
i_C6H14_Concentration	Chemical_Concentration	Concentration of iso-Hexane (i-C6H14).
n_C4H10_Concentration	Chemical_Concentration	Concentration of Normal Butane (n-C4H10); typical volume concentration in natural gas is 0.6%.
n_C5H12_Concentration	Chemical_Concentration	Concentration of Normal Pentane (n-C5H12); typical volume concentration in natural gas is 0.25%.
n_C6H14_Concentration	Chemical_Concentration	Concentration of Normal Hexane (n-C6H14).
pH	Concentration	An indicator of the degree of acidity or basicity of an aqueous solution. A value of 7 denotes a neutral fluid, lower values correspond to acidic fluids and higher values to basic fluids.