<xs:simpleType name="MeasurementType">
  <xs:annotation>
    <xs:documentation>Specifies the type of sensor in a tubular string. The source (except for "CH density porosity", "CH neutron porosity", "OH density porosity" and "OH neutron porosity") of the values and the descriptions is the POSC V2.2 "well log trace class" standard instance values, which are documented as "A classification of well log traces based on specification of a range of characteristics. Traces may be classed according to the type of physical characteristic they are meant to measure."</xs:documentation>
  </xs:annotation>
  <xs:restriction base="eml:TypeEnum">
    <xs:enumeration value="acceleration">
      <xs:annotation>
        <xs:documentation>Output from an accelerometer on a logging tool.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic caliper">
      <xs:annotation>
        <xs:documentation>A well log that uses an acoustic device to measure hole diameter.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic casing collar locator">
      <xs:annotation>
        <xs:documentation>The signal measured by an acoustic device at the location of casing collars and other features (e.g., perforations).</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic impedance">
      <xs:annotation>
        <xs:documentation>Seismic velocity multiplied by density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an acoustic log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic velocity">
      <xs:annotation>
        <xs:documentation>The velocity of an acoustic wave.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic wave matrix travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for an acoustic 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="acoustic wave travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for an acoustic wave to traverse a fixed distance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="amplitude">
      <xs:annotation>
        <xs:documentation>Any measurement of the maximum departure of a wave from an average value.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="amplitude of acoustic wave">
      <xs:annotation>
        <xs:documentation>The extent of departure of an acoustic wave measured from the mean position.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="amplitude of E-M wave">
      <xs:annotation>
        <xs:documentation>The extent of departure of an electromagnetic wave measured from the mean position.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="amplitude ratio">
      <xs:annotation>
        <xs:documentation>The ratio of two amplitudes.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="area">
      <xs:annotation>
        <xs:documentation>A particular extent of space or surface.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="attenuation">
      <xs:annotation>
        <xs:documentation>The amount of reduction in the amplitude of a wave.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="attenuation of acoustic wave">
      <xs:annotation>
        <xs:documentation>The amount of reduction in the amplitude of an acoustic wave.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="attenuation of E-M wave">
      <xs:annotation>
        <xs:documentation>The amount of reduction in the amplitude of an electromagnetic wave.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="auxiliary">
      <xs:annotation>
        <xs:documentation>A general classification for measurements, which are very specialized and not normally accessed by petrophysicists.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="average porosity">
      <xs:annotation>
        <xs:documentation>The pore volume of a rock averaged using various well log or core porosity measurements.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="azimuth">
      <xs:annotation>
        <xs:documentation>In the horizontal plane, it is the clockwise angle of departure from magnetic north (while looking down hole).</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="barite mud correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of barite in the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bed thickness correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for bed thickness effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bit size">
      <xs:annotation>
        <xs:documentation>The diameter of the drill bit used to drill the hole.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="blocked">
      <xs:annotation>
        <xs:documentation>A well log trace that has been edited to reflect sharp bed boundaries. The trace has a square wave appearance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="borehole environment correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of the borehole environment, e.g., borehole size.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="borehole fluid correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of borehole fluid; e.g., a mud cake correction.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="borehole size correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of borehole size.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bromide mud correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of bromide in the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk compressibility">
      <xs:annotation>
        <xs:documentation>The relative compressibility of a material.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk density">
      <xs:annotation>
        <xs:documentation>The measured density of a rock with the pore volume filled with fluid. The pore fluid is generally assumed to be water.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk volume">
      <xs:annotation>
        <xs:documentation>A quantity-per-unit volume.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk volume gas">
      <xs:annotation>
        <xs:documentation>The quantity of gas present in a unit volume of rock. The product of gas saturation and total porosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk volume hydrocarbon">
      <xs:annotation>
        <xs:documentation>The quantity of hydrocarbon present in a unit volume of rock. The product of hydrocarbon saturation and total porosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk volume oil">
      <xs:annotation>
        <xs:documentation>The quantity of oil present in a unit volume of rock. The product of oil saturation and total porosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="bulk volume water">
      <xs:annotation>
        <xs:documentation>The quantity of formation water present in a unit volume of rock. The product of water saturation and total porosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="C/O ratio">
      <xs:annotation>
        <xs:documentation>The ratio of the carbon measurement to the oxygen measurement.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="caliper">
      <xs:annotation>
        <xs:documentation>A well log used to record hole diameter (open or cased).</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cased hole correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of being recorded in a cased hole, e.g., corrected for casing weight and thickness.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="casing collar locator">
      <xs:annotation>
        <xs:documentation>The signal measured by a device at the location of casing collars and other features (e.g., perforations).</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="casing correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of casing; this includes things such as casing weight, thickness and diameter.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="casing diameter correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of casing diameter.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="casing inspection">
      <xs:annotation>
        <xs:documentation>Any of the measurements made for the purpose of determining the properties of the well casing.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="casing thickness correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of casing thickness.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="casing weight correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of casing weight.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cement correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of the cement surrounding the casing; this includes cement thickness, density and type.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cement density correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of cement density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cement evaluation">
      <xs:annotation>
        <xs:documentation>Any of the measurements made to determine the presence and quality of the cement bond to casing or to formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cement thickness correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of cement thickness.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cement type correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of the type of cement used.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="CH density porosity"/>
    <xs:enumeration value="CH dolomite density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of a cased hole density log using a dolomite matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="CH dolomite neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a cased hole neutron log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="CH limestone density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of a cased hole density log using a limestone matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="CH limestone neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a cased-hole neutron log using a limestone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="CH neutron porosity"/>
    <xs:enumeration value="CH sandstone density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of a cased-hole density log using a sandstone matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="CH sandstone neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an openhole neutron log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="compressional wave dolomite porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a compressional wave acoustic log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="compressional wave limestone porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a compressional wave acoustic log using a limestone matrix</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="compressional wave matrix travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for a compressional acoustic 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="compressional wave sandstone porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a compressional wave acoustic log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="compressional wave travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for a compressional acoustic wave to traverse a fixed distance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="conductivity">
      <xs:annotation>
        <xs:documentation>The property of a medium (solid or fluid) that allows the medium to conduct a form of energy; e.g., electrical conductivity or thermal conductivity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="conductivity from attenuation">
      <xs:annotation>
        <xs:documentation>Conductivity calculated from the attenuation of an electromagnetic wave. Generally recorded from a LWD resistivity tool.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="conductivity from phase shift">
      <xs:annotation>
        <xs:documentation>Conductivity calculated from the phase shift of an electromagnetic wave. Generally recorded from a LWD resistivity tool.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="connate water conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of the water entrapped in the interstices of the rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="connate water resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of the water entrapped in the interstices of the rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="conventional core porosity">
      <xs:annotation>
        <xs:documentation>Porosity from a measurement made on a conventional core.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="core matrix density">
      <xs:annotation>
        <xs:documentation>The density of a rock matrix measured on a core sample.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="core permeability">
      <xs:annotation>
        <xs:documentation>The permeability derived from a core.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="core porosity">
      <xs:annotation>
        <xs:documentation>Porosity from a core measurement.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="corrected">
      <xs:annotation>
        <xs:documentation>A trace that has had corrections applied; e.g. environmental corrections.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="count rate">
      <xs:annotation>
        <xs:documentation>The rate of occurrences; e.g. the far counts from a density tool..</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="count rate ratio">
      <xs:annotation>
        <xs:documentation>The ratio of two count rates.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="cross plot porosity">
      <xs:annotation>
        <xs:documentation>The pore volume of a rock calculated from cross plotting two or more well log porosity measurements.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="decay time">
      <xs:annotation>
        <xs:documentation>The time it takes for a population to decay, generally expressed as a half life.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deep conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity that represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deep induction conductivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deep induction resistivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deep laterolog conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity, measured by a laterolog, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deep laterolog resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, measured by a laterolog, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deep resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, which represents a measurement made several feet into the formation; generally considered a measurement of the undisturbed formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="density">
      <xs:annotation>
        <xs:documentation>Mass per unit Volume; well logging units are usually gm/cc.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated using the bulk density measurement from a density log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="depth">
      <xs:annotation>
        <xs:documentation>The distance to a point in a wellbore.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="depth adjusted">
      <xs:annotation>
        <xs:documentation>The process of depth correcting a trace by depth matching it to a reference trace.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="depth derived from velocity">
      <xs:annotation>
        <xs:documentation>The depth calculated from velocity information.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="deviation">
      <xs:annotation>
        <xs:documentation>Departure of a borehole from vertical. Also, the angle measured between the tool axis and vertical.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dielectric">
      <xs:annotation>
        <xs:documentation>Relative permittivity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="diffusion correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of diffusion.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dip">
      <xs:annotation>
        <xs:documentation>The angle that a structural surface, e.g. a bedding or fault plane, makes with the horizontal, measured perpendicular to the strike of the structure.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dipmeter">
      <xs:annotation>
        <xs:documentation>Any of a number of measurements produced by a tool designed to measure formation dip and borehole characteristics through direct and indirect measurements.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dipmeter conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity, measured by a dipmeter, which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids that are comprised primarily of mud filtrate.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dipmeter resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, measured by a dipmeter, which represents a measurement made approximately one to two feet into the formation; generally considered to measure the formation where it contains fluids that are comprised primarily of mud filtrate.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dolomite acoustic porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an acoustic log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dolomite density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of a density log using a dolomite matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="dolomite neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a neutron log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="edited">
      <xs:annotation>
        <xs:documentation>A well log trace which has been corrected or adjusted through an editing process.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="effective porosity">
      <xs:annotation>
        <xs:documentation>The interconnected pore volume occupied by free fluids.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="electric current">
      <xs:annotation>
        <xs:documentation>The flow of electric charge.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="electric potential">
      <xs:annotation>
        <xs:documentation>The difference in electrical energy between two systems.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="electromagnetic wave matrix travel time">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="electromagnetic wave travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for an electromagnetic wave to traverse a fixed distance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="element">
      <xs:annotation>
        <xs:documentation>The elemental composition, generally in weight percent, of a formation as calculated from information obtained from a geochemical logging pass; e.g., weight percent of Al, Si, Ca, Fe, etc.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="elemental ratio">
      <xs:annotation>
        <xs:documentation>The ratio of two different elemental measurements; e.g. K/U.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="enhanced">
      <xs:annotation>
        <xs:documentation>A well log trace that has been filtered to improve its value; e.g. inverse filtering for better resolution.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="filtered">
      <xs:annotation>
        <xs:documentation>A well log trace which has had a filter applied to it.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="flowmeter">
      <xs:annotation>
        <xs:documentation>A logging tool to measure the rate and/or direction of fluid flow in a wellbore.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="fluid density">
      <xs:annotation>
        <xs:documentation>The quantity per unit volume of fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="fluid velocity">
      <xs:annotation>
        <xs:documentation>The velocity of a flowing fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="fluid viscosity">
      <xs:annotation>
        <xs:documentation>The amount of a fluid resistance to flow.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="flushed zone conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of the zone immediately behind the mud cake and which is considered to be flushed by mud filtrate, i.e., it is considered to have all mobile formation fluids displaced from it.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="flushed zone resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of the zone immediately behind the mud cake and which is considered to be flushed by mud filtrate, i.e., it is considered to have all mobile formation fluids displaced from it.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="flushed zone saturation">
      <xs:annotation>
        <xs:documentation>The fraction or percentage of pore volume of rock occupied by drilling mud or mud filtrate in the flushed zone.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="force">
      <xs:annotation>
        <xs:documentation>Energy exerted or brought to bear.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation density correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for formation density effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation properties correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for formation properties; e.g., salinity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation salinity correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the salinity effects from the water in the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation saturation correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for formation saturation effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation volume factor correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of the hydrocarbon formation volume factor.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation water density correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of the density of the formation water.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="formation water saturation correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for water saturation effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="free fluid index">
      <xs:annotation>
        <xs:documentation>The percent of the bulk volume occupied by fluids that are free to flow as measured by the nuclear magnetism log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="friction effect correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of friction.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="gamma ray">
      <xs:annotation>
        <xs:documentation>The measurement of naturally occurring gamma ray radiation being released by radioisotopes in clay or other minerals in the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="gamma ray minus uranium">
      <xs:annotation>
        <xs:documentation>The measurement of the naturally occurring gamma radiation less the radiation attributed to uranium.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="gas saturation">
      <xs:annotation>
        <xs:documentation>The fraction or percentage of pore volume of rock occupied by gas.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="gradiomanometer">
      <xs:annotation>
        <xs:documentation>The measurement of the average density of fluids in a wellbore.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="high frequency conductivity">
      <xs:annotation>
        <xs:documentation>A measurement of the conductivity of the formation, by a high frequency electromagnetic tool, within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="high frequency electromagnetic">
      <xs:annotation>
        <xs:documentation>High frequency electromagnetic measurements, e.g. from a dielectric logging tool.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="high frequency electromagnetic porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated using a high frequency electromagnetic measurement as input.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="high frequency E-M phase shift">
      <xs:annotation>
        <xs:documentation>The amount of change in the phase of a high frequency electromagnetic wave.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="high frequency resistivity">
      <xs:annotation>
        <xs:documentation>A measurement of the resistivity of the formation, by a high frequency electromagnetic tool, within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="hydrocarbon correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of hydrocarbons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="hydrocarbon density correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of hydrocarbon density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="hydrocarbon gravity correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of hydrocarbon gravity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="hydrocarbon saturation">
      <xs:annotation>
        <xs:documentation>The fraction or percentage of pore volume of rock occupied by hydrocarbon.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="hydrocarbon viscosity correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of hydrocarbon viscosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="image">
      <xs:annotation>
        <xs:documentation>The likeness of an object produced by an electrical device.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="interpretation variable">
      <xs:annotation>
        <xs:documentation>A variable in a well log interpretation equation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="iron mud correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of iron in the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="joined">
      <xs:annotation>
        <xs:documentation>A well log trace that has had two or more runs spliced together to make a single trace.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="KCl mud correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for the effects of KCl in the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="length">
      <xs:annotation>
        <xs:documentation>A measured distance or dimension.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="limestone acoustic porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an acoustic log using a limestone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="limestone density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of a density log using a limestone matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="limestone neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a neutron log using a limestone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="lithology correction">
      <xs:annotation>
        <xs:documentation>A trace that has been corrected for lithology effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="log derived permeability">
      <xs:annotation>
        <xs:documentation>The permeability derived from a well log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="log matrix density">
      <xs:annotation>
        <xs:documentation>The density of a rock matrix used with, or derived from, the bulk density from a well log. The matrix is assumed to have zero porosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="magnetic casing collar locator">
      <xs:annotation>
        <xs:documentation>The signal measured by a magnetic device at the location of casing collars and other features (e.g., perforations).</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="matrix density">
      <xs:annotation>
        <xs:documentation>The density of a rock matrix. In this case, the matrix is assumed to have zero porosity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="matrix travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for an electromagnetic or acoustic 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="measured depth">
      <xs:annotation>
        <xs:documentation>The distance measured along the path of a wellbore.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mechanical caliper">
      <xs:annotation>
        <xs:documentation>A well log which uses a mechanical device to measure hole diameter.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mechanical casing collar locator">
      <xs:annotation>
        <xs:documentation>The signal measured by a mechanical device at the location of casing collars and other features (e.g., perforations).</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="medium conductivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="medium induction conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity, made by an induction log, which represents a measurement made approximately two to three feet into the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="medium induction resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, made by an induction log, which represents a measurement made approximately two to three feet into the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="medium laterolog conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity, measured by a laterolog, which represents a measurement made approximately two to three feet into the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="medium laterolog resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, measured by a laterolog, which represents a measurement made approximately two to three feet into the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="medium resistivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro conductivity">
      <xs:annotation>
        <xs:documentation>A measurement of the conductivity of the formation within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro inverse conductivity">
      <xs:annotation>
        <xs:documentation>A conductivity measurement made by a micro log tool which measures within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro inverse resistivity">
      <xs:annotation>
        <xs:documentation>A resistivity measurement made by a micro log tool which measures within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro laterolog conductivity">
      <xs:annotation>
        <xs:documentation>A measurement of the conductivity of the formation, by a laterolog, within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro laterolog resistivity">
      <xs:annotation>
        <xs:documentation>A measurement of the resistivity of the formation, by a laterolog, within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro normal conductivity">
      <xs:annotation>
        <xs:documentation>A conductivity measurement made by a micro log tool which measures within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro normal resistivity">
      <xs:annotation>
        <xs:documentation>A resistivity measurement made by a micro log tool which measures within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro resistivity">
      <xs:annotation>
        <xs:documentation>A measurement of the resistivity of the formation within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro spherically focused conductivity">
      <xs:annotation>
        <xs:documentation>A measurement of the conductivity of the formation, by a spherically focused tool, within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="micro spherically focused resistivity">
      <xs:annotation>
        <xs:documentation>A measurement of the resistivity of the formation, by a spherically focused tool, within the first few cubic inches of the borehole wall.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mineral">
      <xs:annotation>
        <xs:documentation>The mineral composition, generally in weight percent, of a formation as calculated from elemental information obtained from a geochemical logging pass; e.g., weight percent of dolomite, calcite, illite, quartzite, etc.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud cake conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of the filter cake, the residue deposited on the borehole wall as mud loses filtrate into porous and permeable rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud cake correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud cake; e.g., mud cake thickness and/or density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud cake density correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud cake density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud cake resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of the filter cake, the residue deposited on the borehole wall as mud loses filtrate into porous and permeable rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud cake resistivity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud cake resistivity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud cake thickness correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud cake thickness.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud composition correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of borehole fluid composition; e.g., a correction for KCl in the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of the continuous phase liquid used for the drilling of the well.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud filtrate conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of the effluent of the continuous phase liquid of the drilling mud which permeates porous and permeable rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud filtrate correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud filtrate. This includes things such as filtrate salinity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud filtrate density correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud filtrate density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud filtrate resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of the effluent of the continuous phase liquid of the drilling mud which permeates porous and permeable rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud filtrate resistivity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud filtrate resistivity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud filtrate salinity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of mud filtrate salinity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of the continuous phase liquid used for the drilling of the well.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud salinity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of salinity in the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud viscosity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of the viscosity of the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="mud weight correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of weighting the borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="neutron die away time">
      <xs:annotation>
        <xs:documentation>The time it takes for a neutron population to die away to half value.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity from a neutron log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="nuclear caliper">
      <xs:annotation>
        <xs:documentation>A well log which uses a nuclear device to measure hole diameter.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="nuclear magnetic decay time">
      <xs:annotation>
        <xs:documentation>The decay time of a nuclear magnetic signal.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="nuclear magnetism log permeability">
      <xs:annotation>
        <xs:documentation>The permeability derived from a nuclear magnetism log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="nuclear magnetism porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated using the measurements from a nuclear magnetism logging pass.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="OH density porosity"/>
    <xs:enumeration value="OH dolomite density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of an open hole density log using a dolomite matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="OH dolomite neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an open hole neutron log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="OH limestone density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of an open hole density log using a limestone matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="OH limestone neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an open hole neutron log using a limestone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="OH neutron porosity"/>
    <xs:enumeration value="OH sandstone density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of an open hole density log using a sandstone matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="OH sandstone neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an open hole neutron log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="oil based mud correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of oil based borehole fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="oil saturation">
      <xs:annotation>
        <xs:documentation>The fraction or percentage of pore volume of rock occupied by oil.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="perforating">
      <xs:annotation>
        <xs:documentation>The procedure for introducing holes through casing into a formation so that formation fluids can enter into the casing.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="permeability">
      <xs:annotation>
        <xs:documentation>The permeability of the surrounding formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="phase shift">
      <xs:annotation>
        <xs:documentation>A change or variation according to a harmonic law from a standard position or instant of starting.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="photoelectric absorption">
      <xs:annotation>
        <xs:documentation>The effect measured by the density log and produced by the process of a photon colliding with an atom, and then being completely absorbed and its total energy used to eject one of the orbital electrons from those surrounding the nucleus.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="photoelectric absorption correction">
      <xs:annotation>
        <xs:documentation>The correction that is to be made to the photoelectric absorption curve.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="physical measurement correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for various physical measurement effects; e.g. spreading loss.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="plane angle">
      <xs:annotation>
        <xs:documentation>An angle formed by two intersecting lines.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="porosity">
      <xs:annotation>
        <xs:documentation>The total pore volume occupied by fluid in a rock. Includes isolated nonconnecting pores and volume occupied by absorbed, immobile fluid.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="porosity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for porosity effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="potassium">
      <xs:annotation>
        <xs:documentation>The measurement of gamma radiation emitted by potassium.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="pressure">
      <xs:annotation>
        <xs:documentation>The force or thrust exerted upon a surface divided by the area of the surface.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="pressure correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of pressure in the borehole.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="processed">
      <xs:annotation>
        <xs:documentation>A well log trace which has been processed in some way; e.g., depth adjusted or environmentally corrected.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="pulsed neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a pulsed neutron log.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="quality">
      <xs:annotation>
        <xs:documentation>Degree of excellence.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="ratio">
      <xs:annotation>
        <xs:documentation>A relationship between two values usually expressed as a fraction.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="raw">
      <xs:annotation>
        <xs:documentation>A well log trace which has not had any processing. In other words, a trace which has not been depth adjusted or environmentally corrected.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="relative bearing">
      <xs:annotation>
        <xs:documentation>While looking down hole, it is the clockwise angle from the upper side of the sonde to the reference pad or electrode.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="resistivity">
      <xs:annotation>
        <xs:documentation>The property measuring the resistance to flow of an electrical current.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="resistivity factor correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for resistivity factor effects.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="resistivity from attenuation">
      <xs:annotation>
        <xs:documentation>Resistivity calculated from the attenuation of an electromagnetic wave. Generally recorded from a LWD resistivity tool.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="resistivity from phase shift">
      <xs:annotation>
        <xs:documentation>Resistivity calculated from the phase shift of an electromagnetic wave. Generally recorded from a LWD resistivity tool.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="resistivity phase shift">
      <xs:annotation>
        <xs:documentation>The amount of change in the phase of an electrical wave.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="resistivity ratio">
      <xs:annotation>
        <xs:documentation>The ratio of two resistivity values.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="salinity">
      <xs:annotation>
        <xs:documentation>The concentration of ions in solution.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sampling">
      <xs:annotation>
        <xs:documentation>To take a sample of or from something.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sandstone acoustic porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from an acoustic log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sandstone density porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from the bulk density measurement of a density log using a sandstone matrix density.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sandstone neutron porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a neutron log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="saturation">
      <xs:annotation>
        <xs:documentation>The fraction or percentage of the pore volume of a rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shale volume">
      <xs:annotation>
        <xs:documentation>An estimate of the amount of shale present in the formation. Frequently calculated from a gamma ray or SP curve.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shallow conductivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shallow induction conductivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shallow induction resistivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shallow laterolog conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity, measured by a laterolog, 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shallow laterolog resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, measured by a laterolog, 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shallow resistivity">
      <xs:annotation>
        <xs:documentation>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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shear wave dolomite porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a shear wave acoustic log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shear wave limestone porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a shear wave acoustic log using a limestone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shear wave matrix travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for a shear acoustic 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shear wave sandstone porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a shear wave acoustic log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shear wave travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for a shear acoustic wave to traverse a fixed distance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="shifted">
      <xs:annotation>
        <xs:documentation>A well log trace which has had its original values shifted by some factor; e.g., added or multiplied by a constant.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sidewall core porosity">
      <xs:annotation>
        <xs:documentation>Porosity from a measurement made on a sidewall core.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma formation">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of the formation for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma gas">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of gas for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma hydrocarbon">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of hydrocarbon for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma matrix">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of the rock matrix for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma oil">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of oil for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="sigma water">
      <xs:annotation>
        <xs:documentation>The macroscopic capture cross section, i.e. the effective cross-sectional area per unit volume, of water for the capture of neutrons.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="slippage velocity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for slippage velocity.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="smoothed">
      <xs:annotation>
        <xs:documentation>A well log trace which has been filtered to smooth, or average the trace.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="spectral gamma ray">
      <xs:annotation>
        <xs:documentation>The measurement of all the naturally occurring gamma radiation separated by energy windows.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="spherically focused conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity, measured by a spherically focused log, which represents the resistivity approximately one to two feet into the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="spherically focused resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity, measured by a spherically focused log, which represents the resistivity approximately one to two feet into the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="spontaneous potential">
      <xs:annotation>
        <xs:documentation>The difference in potential (DC Voltage) between a moveable electrode in the borehole and a distant reference electrode usually at the surface.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="spreading loss correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of spreading loss.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="synthetic well log trace">
      <xs:annotation>
        <xs:documentation>A well log trace which has been artificially created, as opposed to an actual measurement, from associated measurements or information.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="temperature">
      <xs:annotation>
        <xs:documentation>A temperature measurement.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="temperature correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of the temperature in the borehole.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tension">
      <xs:annotation>
        <xs:documentation>The tension on the wireline cable while logging.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="Th/K ratio">
      <xs:annotation>
        <xs:documentation>The ratio of the Thorium measurement to the Potassium measurement.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="thorium">
      <xs:annotation>
        <xs:documentation>The measurement of gamma radiation emitted by thorium.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="time">
      <xs:annotation>
        <xs:documentation>A measured or measurable period.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tool diameter correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the tool diameter.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tool eccentricity correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of the tool not being centered in the borehole.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="total gamma ray">
      <xs:annotation>
        <xs:documentation>The measurement of all the naturally occurring gamma radiation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="total porosity">
      <xs:annotation>
        <xs:documentation>The total pore volume occupied by fluid in a rock.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tracer survey">
      <xs:annotation>
        <xs:documentation>A well log used for the purpose of monitoring a traceable material; e.g. a radioactive isotope.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for an acoustic or electromagnetic wave to traverse a specific distance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="true conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of fluid-filled rock where fluid distributions and saturations are representative of those in the uninvaded, undisturbed part of the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="true resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of fluid-filled rock where fluid distributions and saturations are representative of those in the uninvaded, undisturbed part of the formation.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="true vertical depth">
      <xs:annotation>
        <xs:documentation>The distance along a straight, vertical path. Usually computed from a measured depth and deviation information.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tube wave dolomite porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a tube wave acoustic log using a dolomite matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tube wave limestone porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a tube wave acoustic log using a limestone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tube wave matrix travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for a acoustic tube 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.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tube wave sandstone porosity">
      <xs:annotation>
        <xs:documentation>Porosity calculated from a tube wave acoustic log using a sandstone matrix.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="tube wave travel time">
      <xs:annotation>
        <xs:documentation>The time it takes for a tube acoustic wave to traverse a fixed distance.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="uranium">
      <xs:annotation>
        <xs:documentation>The measurement of gamma radiation emitted by uranium.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="velocity">
      <xs:annotation>
        <xs:documentation>directional speed</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="volume">
      <xs:annotation>
        <xs:documentation>cubic capacity</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="water based fluid correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for the effects of the components in a water based borehole fluid system; e.g., a correction for KCL in the mud.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="water holdup correction">
      <xs:annotation>
        <xs:documentation>A trace which has been corrected for water holdup.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="water saturated conductivity">
      <xs:annotation>
        <xs:documentation>The conductivity of rock completely saturated with connate water.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="water saturated resistivity">
      <xs:annotation>
        <xs:documentation>The resistivity of rock completely saturated with connate water.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="water saturation">
      <xs:annotation>
        <xs:documentation>The fraction or percentage of pore volume of rock occupied by water.</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
  </xs:restriction>
</xs:simpleType>