Methods of processing well logging data

Claim 1

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; deriving third measurements functionally related to the resistivity of the formation along the borehole section; combining said first, second and third measurements to produce output representations functionally related to one or more formation parameters including the shale or clay content, porosity, or water or hydrocarbon saturation of the formation; comparing one or more of said output representations with each other or predetermined limit values to determine feasibility of said compared output representations; and computing new values for one or more of said shale or clay content, porosity, or water or hydrocarbon saturation if said compared output representations are not feasible.

Claim 2

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; deriving third measurements functionally related to the resistivity of the formation along the borehole section; combining said first, second and third measurements to produce output representations functionally related to one or more formation parameters including the shale or clay content, porosity, or water or hydrocarbon saturation of the formation; comparing one or more of said output representations with each other or predetermined limit values to determine feasibility of said compared output representations; and computing new values for one or more of said shale or clay content, porosity, or water or hydrocarbon saturation if said compared output representations are not feasible.

Claim 4

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; combining said first and second measurements to produce indications of formation clay content and formation gas saturation along the section of a borehole, each of said indications being functionally related to both of said first and second measurements; deriving third measurements along a section of a borehole of one ore more of the spontaneous naturally occurring potential of a formation, the natural radioactivity of a formation, or the diameter of a borehole; detecting if a third measurement exceeds a given limit; and inhibiting the combination of said first and second measurements if said third measurement exceeds said given limit.

Claim 5

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; combining said first and second measurements to produce indications of formation clay content and formation gas saturation along the section of a borehole, each of said indications being functionally related to both of said first and second measurements; deriving third measurements along a section of a borehole of one ore more of the spontaneous naturally occurring potential of a formation, the natural radioactivity of a formation, or the diameter of a borehole; detecting if a third measurement exceeds a given limit; and inhibiting the combination of said first and second measurements if said third measurement exceeds said given limit.

Claim 6

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; combining said first and second measurements to produce indications of formation clay content and formation gas saturation along the section of a borehole, each of said indications being functionally related to both of said first and second measurements; deriving third measurements along a section of a borehole of the spontaneous naturally occurRing potential of the formations traversed by the borehole; deriving fourth measurements along a section of a borehole of the electrical resistivity of the formations traversed by the well bore; detecting if a third measurement exceeds a first limit; detecting if a fourth measurement exceeds a second limit; and inhibiting the combination of said first and second measurements in response to a third measurement exceeding said first limit unless a fourth measurement exceeds said second limit.

Claim 7

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; combining said first and second measurements to produce indications of formation clay content and formation gas saturation along the section of a borehole, each of said indications being functionally related to both of said first and second measurements; deriving third measurements along a section of a borehole of the spontaneous naturally occurRing potential of the formations traversed by the borehole; deriving fourth measurements along a section of a borehole of the electrical resistivity of the formations traversed by the well bore; detecting if a third measurement exceeds a first limit; detecting if a fourth measurement exceeds a second limit; and inhibiting the combination of said first and second measurements in response to a third measurement exceeding said first limit unless a fourth measurement exceeds said second limit.

Claim 8

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to the formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements phi D functionally related to the formation bulk density along a section of a borehole; and combining said first and second measurements to provide values of formation clay content q, formation gas saturation Sgxo, and effective nonclay filled porosity phi e along a section of a borehole in accordance with the relationships: phi D phi e + 0.5 phi e Sgxo, phi N phi e + q phi z - 0.7 phi e Sgxo, and phi e phi z (1 - q), and wherein the total formation porosity phi z is a predetermined parameter.

Claim 9

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to the formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements phi D functionally related to the formation bulk density along a section of a borehole; and combining said first and second measurements to provide values of formation clay content q, formation gas saturation Sgxo, and effective nonclay filled porosity phi e along a section of a borehole in accordance with the relationships: phi D phi e + 0.5 phi e Sgxo, phi N phi e + q phi z - 0.7 phi e Sgxo, and phi e phi z (1 - q), and wherein the total formation porosity phi z is a predetermined parameter.

Claim 10

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of formations at the selected depth level, said total porosity indication being an assumed value ascertained from said first and second measurements taken at selected formation depth levels; combining said total porosity indication with said first and second measurements to produce an indication of the formation clay content at the selected depth level; testing said clay content indication to determine if said clay content indication is within a given limit; and adjusting said total porosity indication if said clay content indication is outside of said given limit and recombining said adjusted total porosity indication with said first and second measurements to produce a new and more accurate indication of formation clay content at the selected depth level.

Claim 11

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of formations at the selected depth level, said total porosity indication being an assumed value ascertained from said first and second measurements taken at selected formation depth levels; combining said total porosity indication with said first and second measurements to produce an indication of the formation clay content at the selected depth level; testing said clay content indication to determine if said clay content indication is within a given limit; and adjusting said total porosity indication if said clay content indication is outside of said given limit and recombining said adjusted total porosity indication with said first and second measurements to produce a new and more accurate indication of formation clay content at the selected depth level.

Claim 12

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of a formation at the selected depth level, said total porosity indication being an assumed value ascertained from said first and second measurements taken at various formation depth levels; combining said total porosity indication with said first and second measurements to produce indications of the gas saturation in a zone near a borehole, and formation clay content at the selected depth level, each of said indications being functionally related to both of said derived measurements; deriving a third measurement representative of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said clay content and total porosity indications to produce an indication of hydrocarbon saturation in said formation zone radially spaced from a borehole at the selected depth level; comparing said gas and hydrocarbon indications to determine if said gas saturation indication is greater than a given percentage of said hydrocarbon saturation indication; and adjusting said total porosity indication if said gas saturation indication is outside of said given percentage limit and recombining said adjusted total porosity indication with said first, second and third measurements to produce new indications of formation clay content, and hydrocarbon and gas saturation at the selected depth level.

Claim 13

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of a formation at the selected depth level, said total porosity indication being an assumed value ascertained from said first and second measurements taken at various formation depth levels; combining said total porosity indication with said first and second measurements to produce indications of the gas saturation in a zone near a borehole, and formation clay content at the selected depth level, each of said indications being functionally related to both of said derived measurements; deriving a third measurement representative of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said clay content and total porosity indications to produce an indication of hydrocarbon saturation in said formation zone radially spaced from a borehole at the selected depth level; comparing said gas and hydrocarbon indications to determine if said gas saturation indication is greater than a given percentage of said hydrocarbon saturation indication; and adjusting said total porosity indication if said gas saturation indication is outside of said given percentage limit and recombining said adjusted total porosity indication with said first, second and third measurements to produce new indications of formation clay content, and hydrocarbon and gas saturation at the selected depth level.

Claim 14

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said first and second measurements to produce indications of formation gas saturation in a zone near a borehole, and formation clay content at the selected depth level, each of said indications being functionally related to both of said derived measurements; deriving a third measurement representative of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said clay content indication to produce an indication of formation hydrocarbon saturation in a zone radially spaced from a borehole; and recording said gas and hydrocarbon saturation indications whereby the relationship of said gas and hydrocarbon indications to one another is indicative of the presence of oil or gas in a formation at the selected depth level.

Claim 15

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said first and second measurements to produce indications of formation gas saturation in a zone near a borehole, and formation clay content at the selected depth level, each of said indications being functionally related to both of said derived measurements; deriving a third measurement representative of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said clay content indication to produce an indication of formation hydrocarbon saturation in a zone radially spaced from a borehole; and recording said gas and hydrocarbon saturation indications whereby the relationship of said gas and hydrocarbon indications to one another is indicative of the presence of oil or gas in a formation at the selected depth level.

Claim 16

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of a formation, said total porosity indication being an assumed value ascertained from said first and second measurements taken at selected formation depth levels; combining said total porosity indication with said first and second measurements to produce indications of formation clay content and the effective nonclay filled porosity of a formation at the selected depth level, each of said clay content and effective porosity indications being functionally related to both of said derived measurements and said total porosity indication; testing said clay content indication to determine if said clay content indication is within a given limit; adjusting said total porosity indication if said clay content indication is outside of said given limit and recombining said adjusted total porosity indication with said first and second measurements to produce a new indication of formation clay content at the selected depth level; deriving a third measurement representative of the electrical resistivity of a formation at the selected depth level; combining said third measurement with said adjusted total porosity indication, said new clay content indication, and said effective porosity indication to produce an indication of the amount of bulk volume formation filled with water at the selected depth level; and recording said total porosity, effective porosity, and bulk volume water indications on a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of bulk volume clay content and the separation between said effective porosity and bulk volume water logs is indicative of bulk volume hydrocarbons at the selected depth level.

Claim 17

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of a formation, said total porosity indication being an assumed value ascertained from said first and second measurements taken at selected formation depth levels; combining said total porosity indication with said first and second measurements to produce indications of formation clay content and the effective nonclay filled porosity of a formation at the selected depth level, each of said clay content and effective porosity indications being functionally related to both of said derived measurements and said total porosity indication; testing said clay content indication to determine if said clay content indication is within a given limit; adjusting said total porosity indication if said clay content indication is outside of said given limit and recombining said adjusted total porosity indication with said first and second measurements to produce a new indication of formation clay content at the selected depth level; deriving a third measurement representative of the electrical resistivity of a formation at the selected depth level; combining said third measurement with said adjusted total porosity indication, said new clay content indication, and said effective porosity indication to produce an indication of the amount of bulk volume formation filled with water at the selected depth level; and recording said total porosity, effective porosity, and bulk volume water indications on a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of bulk volume clay content and the separation between said effective porosity and bulk volume water logs is indicative of bulk volume hydrocarbons at the selected depth level.

Claim 18

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of a formation, said total porosity indication being an assumed value ascertained from said first and second measurements taken at selected formation depth levels; combining the total porosity indication with said first and second measurements to produce indications of formation clay content, formation gas saturation in a zone near a borehole, and the effective, nonclay filled porosity of a formation at the selected depth level, each of said clay content, gas saturation, and effective porosity indications being functionally related to said derived measurements and said total porosity indication; testing said clay content and gas saturation indications to determine if said clay content and gas saturation indications are within given limits; adjusting said total porosity indication if said clay content and gas saturation indications are outside of said given limits and recombining said adjusted total porosity indication with said first and second measurements to produce new indications of formation clay content and gas saturation at the selected depth level; deriving a third measurement representative of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said adjusted total porosity indication and said new clay content indication to produce indications of formation water and hydrocarbon saturation in said radially spaced formation zone at the selected depth level; combining said formation effective porosity and water saturation indications to give an indication of the amount of bulk volume formation filled with water at the selected depth level; recording said total porosity, effective porosity, bulk volume water indications on one track of a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of bulk volume clay content at the selected depth level and the separation between said effective porosity and bulk volume water logs is indicative of bulk volume hydrocarbon content at the selected depth level; and recording said gas and hydrocarbon saturation indications on one track of a record medium to produce logs thereof whereby a comparison of said gas and hydrocarbon saturation logs will provide information as to whether a formation at the selected depth level contains gas or oil.

Claim 19

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; providing an indication of the total porosity of a formation, said total porosity indication being an assumed value ascertained from said first and second measurements taken at selected formation depth levels; combining the total porosity indication with said first and second measurements to produce indications of formation clay content, formation gas saturation in a zone near a borehole, and the effective, nonclay filled porosity of a formation at the selected depth level, each of said clay content, gas saturation, and effective porosity indications being functionally related to said derived measurements and said total porosity indication; testing said clay content and gas saturation indications to determine if said clay content and gas saturation indications are within given limits; adjusting said total porosity indication if said clay content and gas saturation indications are outside of said given limits and recombining said adjusted total porosity indication with said first and second measurements to produce new indications of formation clay content and gas saturation at the selected depth level; deriving a third measurement representative of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said adjusted total porosity indication and said new clay content indication to produce indications of formation water and hydrocarbon saturation in said radially spaced formation zone at the selected depth level; combining said formation effective porosity and water saturation indications to give an indication of the amount of bulk volume formation filled with water at the selected depth level; recording said total porosity, effective porosity, bulk volume water indications on one track of a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of bulk volume clay content at the selected depth level and the separation between said effective porosity and bulk volume water logs is indicative of bulk volume hydrocarbon content at the selected depth level; and recording said gas and hydrocarbon saturation indications on one track of a record medium to produce logs thereof whereby a comparison of said gas and hydrocarbon saturation logs will provide information as to whether a formation at the selected depth level contains gas or oil.

Claim 20

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi s functionally related to formation acoustic travel time along a section of a borehole traversing earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; and combining said first and second measurements to produce indications of formation gas saturation Sgxo and the effective, nonclay filled formation porosity phi e along a section of a borehole in accordance with the relationships: phi s phi e + (Cp-1) phi e Sgxo, phi D phi e + 0.5 phi e Sgxo, and wherein the formation compaction factor Cp is a predetermined parameter.

Claim 21

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi s functionally related to formation acoustic travel time along a section of a borehole traversing earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; and combining said first and second measurements to produce indications of formation gas saturation Sgxo and the effective, nonclay filled formation porosity phi e along a section of a borehole in accordance with the relationships: phi s phi e + (Cp-1) phi e Sgxo, phi D phi e + 0.5 phi e Sgxo, and wherein the formation compaction factor Cp is a predetermined parameter.

Claim 22

A method of machine processing well logging data derived from exploring devices which inVestigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation clay content at the selected depth level; testing said clay content indication to determine if said clay content indication is within a given limit; and adjusting said compaction factor indication if said clay content indication is outside of said given limit and recombining said second measurement with said adjusted compaction factor indication and acoustic travel time measurement to produce a new indication of clay content at the selected depth level.

Claim 23

A method of machine processing well logging data derived from exploring devices which inVestigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation clay content at the selected depth level; testing said clay content indication to determine if said clay content indication is within a given limit; and adjusting said compaction factor indication if said clay content indication is outside of said given limit and recombining said second measurement with said adjusted compaction factor indication and acoustic travel time measurement to produce a new indication of clay content at the selected depth level.

Claim 26

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing indications of a formation compaction factor representative of the compactness of a formation at the selected depth level and the acoustic matrix travel time of the solid material of a formation at the selected depth level, said compaction factor and matrix travel time indications being ascertained from well logging data measured at selected formation depth levels; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation clay content at the selected depth level; testing said clay content indication to determine if said clay content indication is within a given limit; and adjusting one of said compaction factor or matrix travel time indications if said clay content indication is outside of said given limit, said compaction factor indication being adjusted until exceeding a given limit at which time said matrix travel time indication is adjusted, and recombining said adjusted compaction factor or matrix travel time indications with said acoustic travel time measurement to produce a new Acoustic travel time derived porosity indication for recombination with said second measurement to produce a new indication of clay content at the selected depth level.

Claim 27

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing indications of a formation compaction factor representative of the compactness of a formation at the selected depth level and the acoustic matrix travel time of the solid material of a formation at the selected depth level, said compaction factor and matrix travel time indications being ascertained from well logging data measured at selected formation depth levels; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation clay content at the selected depth level; testing said clay content indication to determine if said clay content indication is within a given limit; and adjusting one of said compaction factor or matrix travel time indications if said clay content indication is outside of said given limit, said compaction factor indication being adjusted until exceeding a given limit at which time said matrix travel time indication is adjusted, and recombining said adjusted compaction factor or matrix travel time indications with said acoustic travel time measurement to produce a new Acoustic travel time derived porosity indication for recombination with said second measurement to produce a new indication of clay content at the selected depth level.

Claim 28

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce indications of formation clay content, total formation porosity, and effective nonclay filled formation porosity at the selected depth level, each of said clay content, total and effective porosity indications being functionally related to said acoustic porosity indication and second porosity measurement; testing said clay content indication to determine if said clay content indication is within a given limit; adjusting said compaction factor indication if said clay content indication is outside of said given limit and recombining said second measurement with said adjusted compaction factor indication and acoustic travel time measurement to produce new indications of clay content, total and effective porosity at the selected depth level; deriving a third measurement representative of the electrical resistivity of a formation at the selected depth level; combining said third measurement with said new indications of clay content, total and effective porosity to produce an indication of that portion of the formation bulk volume filled with water at the selected depth level; and recording said bulk volume water and total and effective porosity indications on a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of bulk volume clay content and the separation between the effective porosity and bulk volume water logs is indicative of bulk volume hydrocarbon content.

Claim 29

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce indications of formation clay content, total formation porosity, and effective nonclay filled formation porosity at the selected depth level, each of said clay content, total and effective porosity indications being functionally related to said acoustic porosity indication and second porosity measurement; testing said clay content indication to determine if said clay content indication is within a given limit; adjusting said compaction factor indication if said clay content indication is outside of said given limit and recombining said second measurement with said adjusted compaction factor indication and acoustic travel time measurement to produce new indications of clay content, total and effective porosity at the selected depth level; deriving a third measurement representative of the electrical resistivity of a formation at the selected depth level; combining said third measurement with said new indications of clay content, total and effective porosity to produce an indication of that portion of the formation bulk volume filled with water at the selected depth level; and recording said bulk volume water and total and effective porosity indications on a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of bulk volume clay content and the separation between the effective porosity and bulk volume water logs is indicative of bulk volume hydrocarbon content.

Claim 30

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation gas saturation at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; and adjusting said compaction factor indication if said gas saturation indication is outside of said given limit and recombining said second measurement with said adjusted compaction factor indication and acoustic travel time measurement to produce a new indication of gas saturation at the selected depth level.

Claim 31

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation gas saturation at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; and adjusting said compaction factor indication if said gas saturation indication is outside of said given limit and recombining said second measurement with said adjusted compaction factor indication and acoustic travel time measurement to produce a new indication of gas saturation at the selected depth level.

Claim 32

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selectEd borehole depth level; providing indications of a formation compaction factor representative of the compactness of a formation and the acoustic matrix travel time of the solid material of a formation at the selected depth level, said compaction factor and matrix travel time indications being ascertained from well logging data measured at selected formation depth levels; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation gas saturation at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; and adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is outside of said given limit, said compaction factor indication being adjusted until exceeding a given limit at which time said matrix travel time indication is adjusted, and recombining said adjusted compaction factor or matrix travel time indications with said acoustic travel time measurement to produce a new acoustic travel time derived porosity indication for recombination with said second measurement to produce a new indication of gas saturation at the selected depth level.

Claim 33

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selectEd borehole depth level; providing indications of a formation compaction factor representative of the compactness of a formation and the acoustic matrix travel time of the solid material of a formation at the selected depth level, said compaction factor and matrix travel time indications being ascertained from well logging data measured at selected formation depth levels; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce an indication of formation gas saturation at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; and adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is outside of said given limit, said compaction factor indication being adjusted until exceeding a given limit at which time said matrix travel time indication is adjusted, and recombining said adjusted compaction factor or matrix travel time indications with said acoustic travel time measurement to produce a new acoustic travel time derived porosity indication for recombination with said second measurement to produce a new indication of gas saturation at the selected depth level.

Claim 34

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing indications of a formation compaction factor representative of the compactness of a formation and the acoustic matrix travel time of the solid material of a formation at the selected depth level, said compaction factor and matrix travel time indications being ascertained from well logging data measured at selected formation depth levels; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce indications of formation gas saturation in a zone close to a borehole and total formation porosity at the selected depth levels, each of said gas saturation and total porosity indications being functionally related to said acoustic porosity indication and second measurement; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is outside of said given limit, said compaction factor indication being adjusted until exceeding a given limit at which time said matrix travel time indication is adjusted, and recombining said adjusted compaction factor or matrix travel time indications with said acoustic travel time measurement to produce a new acoustic travel time derived porosity indication for recombination with said second measurement to produce new indications of gas saturation and total porosity at the selected depth level; deriving a third measurement of the electrical resistivity of a zone radially spaced from a borehole at the selected depth level; combining said third measurement with said new total porosity indication to provide an indication of the hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; and recording said gas and hydrocarbon saturation indications on a record medium to produce logS thereof whereby a comparison of said two logs will indicate the presence of gas or oil in a formation.

Claim 35

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing indications of a formation compaction factor representative of the compactness of a formation and the acoustic matrix travel time of the solid material of a formation at the selected depth level, said compaction factor and matrix travel time indications being ascertained from well logging data measured at selected formation depth levels; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce indications of formation gas saturation in a zone close to a borehole and total formation porosity at the selected depth levels, each of said gas saturation and total porosity indications being functionally related to said acoustic porosity indication and second measurement; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is outside of said given limit, said compaction factor indication being adjusted until exceeding a given limit at which time said matrix travel time indication is adjusted, and recombining said adjusted compaction factor or matrix travel time indications with said acoustic travel time measurement to produce a new acoustic travel time derived porosity indication for recombination with said second measurement to produce new indications of gas saturation and total porosity at the selected depth level; deriving a third measurement of the electrical resistivity of a zone radially spaced from a borehole at the selected depth level; combining said third measurement with said new total porosity indication to provide an indication of the hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; and recording said gas and hydrocarbon saturation indications on a record medium to produce logS thereof whereby a comparison of said two logs will indicate the presence of gas or oil in a formation.

Claim 36

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce indications of formation gas saturation in a zone close to a borehole, and total formation porosity at the selected depth level, each of said gas saturation and total porosity indications being functionally related to said acoustic porosity indication and second measurement; deriving a third measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said total porosity indication to produce an indication of hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; comparing said gas saturation indication with said hydrocarbon saturation indication to determine if said gas saturation indication is greater than a given percentage of said hydrocarbon saturation indication; and adjusting said compaction factor indication if said gas saturation indication is greater than said given percentage and recombining said second measurement with said adjusted compaction factor indication and said acoustic travel time measurement to produce a new gas saturation indication and a new total porosity indication for recombination with said third measurement to produce a new indication of hydrocarbon saturation at the selected depth level.

Claim 37

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first measurement representative of formation acoustic travel time at a selected borehole depth level; providing an indication of a formation compaction factor representative of the compactness of a formation at the selected depth level; combining said first measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; combining said acoustic travel time derived porosity indication with said second measurement to produce indications of formation gas saturation in a zone close to a borehole, and total formation porosity at the selected depth level, each of said gas saturation and total porosity indications being functionally related to said acoustic porosity indication and second measurement; deriving a third measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said third measurement with said total porosity indication to produce an indication of hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; comparing said gas saturation indication with said hydrocarbon saturation indication to determine if said gas saturation indication is greater than a given percentage of said hydrocarbon saturation indication; and adjusting said compaction factor indication if said gas saturation indication is greater than said given percentage and recombining said second measurement with said adjusted compaction factor indication and said acoustic travel time measurement to produce a new gas saturation indication and a new total porosity indication for recombination with said third measurement to produce a new indication of hydrocarbon saturation at the selected depth level.

Claim 38

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements functionally related to the acoustic travel time of a formation along a section of a borehole; and combining said first, second, and third measurements to produce output representations of one or more of formation clay content q, formation effective porosity phi e or formation hydrocarbon saturation Shy along a section of a borehole, said first and second porosity measurements being combined in accordance with the following: phi N f( phi e, q, phi Shy) phi D f( phi e, phi eShy) where f signifies a functional relationship.

Claim 39

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements functionally related to the acoustic travel time of a formation along a section of a borehole; and combining said first, second, and third measurements to produce output representations of one or more of formation clay content q, formation effective porosity phi e or formation hydrocarbon saturation Shy along a section of a borehole, said first and second porosity measurements being combined in accordance with the following: phi N f( phi e, q, phi Shy) phi D f( phi e, phi eShy) where f signifies a functional relationship.

Claim 44

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements functionally related to the acoustic travel time of a formation along a section of a borehole; combining said first, second, and third measurements to produce output representations of one of formation clay content or formation gas saturation along a section of a borehole; deriving fourth measurements of one or more of the spontaneous, naturally occurring potential of a formation, the natural radioactivity of a formation, or the diameter of a borehole along a section of a borehole; detecting if said fourth measurements exceed a given limit; and inhibiting the combination of said first, second and third measurements in response to said fourth measurements exceeding said given limit.

Claim 45

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements functionally related to the acoustic travel time of a formation along a section of a borehole; combining said first, second, and third measurements to produce output representations of one of formation clay content or formation gas saturation along a section of a borehole; deriving fourth measurements of one or more of the spontaneous, naturally occurring potential of a formation, the natural radioactivity of a formation, or the diameter of a borehole along a section of a borehole; detecting if said fourth measurements exceed a given limit; and inhibiting the combination of said first, second and third measurements in response to said fourth measurements exceeding said given limit.

Claim 46

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements functionally related to the acoustic travel time of a formation along a section of a borehole; combining said first, second, and third measurements to produce indications of one of formation clay content or formation gas saturation along a section of a borehole; deriving fourth measurements of the spontaneous, naturally occurring potential of a formation along a section of a borehole; deriving fifth measurements of the electrical resistivity of a formation along a section of a borehole; detecting if a fourth measurement exceeds a first limit; detecting if a fifth measurement exceeds a second limit; and inhibiting the combination of said first, second and third measurements in response to a fourth measurement exceeding said first limit unless a fifth measurement exceeds said second limit.

Claim 47

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements functionally related to the acoustic travel time of a formation along a section of a borehole; combining said first, second, and third measurements to produce indications of one of formation clay content or formation gas saturation along a section of a borehole; deriving fourth measurements of the spontaneous, naturally occurring potential of a formation along a section of a borehole; deriving fifth measurements of the electrical resistivity of a formation along a section of a borehole; detecting if a fourth measurement exceeds a first limit; detecting if a fifth measurement exceeds a second limit; and inhibiting the combination of said first, second and third measurements in response to a fourth measurement exceeding said first limit unless a fifth measurement exceeds said second limit.

Claim 48

A method of machine processing well logging data derived from exploring devices which investigate earth formAtions traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements phi S functionally related to the acoustic travel time of a formation along a section of a borehole; and combining said first, second, and third measurements to produce indications of one or more of formation clay content q, formation hydrocarbon saturation Shy, total formation porosity phi z, or effective, nonclay filled formation porosity phi e along a section of a borehole, said measurements being combined in accordance with the following: phi N f( phi e, q phi z, phi eShy) phi D f( phi e, phi eShy) phi S f( phi e, q phi z, phi Shy) where f signifies a functional relationship.

Claim 49

A method of machine processing well logging data derived from exploring devices which investigate earth formAtions traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements phi S functionally related to the acoustic travel time of a formation along a section of a borehole; and combining said first, second, and third measurements to produce indications of one or more of formation clay content q, formation hydrocarbon saturation Shy, total formation porosity phi z, or effective, nonclay filled formation porosity phi e along a section of a borehole, said measurements being combined in accordance with the following: phi N f( phi e, q phi z, phi eShy) phi D f( phi e, phi eShy) phi S f( phi e, q phi z, phi Shy) where f signifies a functional relationship.

Claim 52

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to formation hydrogen content along a section of a borehole traversed by earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements phi s functionally related to the acoustic travel time of a formation along a section of a borehole; and combining said first, second, and third measurements to produce indications of formation clay content q, formation gas saturation Sgxo, total formation porosity phi z, and effective nonclay filled formation porosity phi e along a section of a borehole in accordance with the relationships: phi N phi e+ q phi z+ (Cp-1) phi eSgxo, phi D phi e+ 0.5 phi eSgxo, and phi s phi e+ q phi z+ (Cp-) phi ) phi eSgxo, where the formation compaction factor Cp is a known quantity.

Claim 53

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements phi N functionally related to formation hydrogen content along a section of a borehole traversed by earth formations; deriving second porosity measurements phi D functionally related to formation bulk density along a section of a borehole; deriving third porosity measurements phi s functionally related to the acoustic travel time of a formation along a section of a borehole; and combining said first, second, and third measurements to produce indications of formation clay content q, formation gas saturation Sgxo, total formation porosity phi z, and effective nonclay filled formation porosity phi e along a section of a borehole in accordance with the relationships: phi N phi e+ q phi z+ (Cp-1) phi eSgxo, phi D phi e+ 0.5 phi eSgxo, and phi s phi e+ q phi z+ (Cp-) phi ) phi eSgxo, where the formation compaction factor Cp is a known quantity.

Claim 54

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements functionally related to formation bulk density along a section of a borehole; deriving third porosity measuRements functionally related to the acoustic travel time of a formation along a section of a borehole; combining said first, second, and third measurements to produce indications of formation clay content, formation gas saturation, total formation porosity, and effective, nonclay filled formation porosity along a section of a borehole, each of said produced indications being functionally related to said first, second and third derived measurements; deriving fourth measurements representative of the electrical resistivity of a formation along a section of a borehole; combining said fourth measurements with said clay content and total and effective porosity indications to produce an indication of the percentage of water of the formation bulk volume along a section of a borehole; and recording said bulk volume water and total and effective porosity indications on one track of a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of the bulk volume clay content along a section of a borehole and the separation between the effective porosity and bulk volume water logs is indicative of the bulk volume hydrocarbon content along a section of a borehole.

Claim 55

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second porosity measurements functionally related to formation bulk density along a section of a borehole; deriving third porosity measuRements functionally related to the acoustic travel time of a formation along a section of a borehole; combining said first, second, and third measurements to produce indications of formation clay content, formation gas saturation, total formation porosity, and effective, nonclay filled formation porosity along a section of a borehole, each of said produced indications being functionally related to said first, second and third derived measurements; deriving fourth measurements representative of the electrical resistivity of a formation along a section of a borehole; combining said fourth measurements with said clay content and total and effective porosity indications to produce an indication of the percentage of water of the formation bulk volume along a section of a borehole; and recording said bulk volume water and total and effective porosity indications on one track of a record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of the bulk volume clay content along a section of a borehole and the separation between the effective porosity and bulk volume water logs is indicative of the bulk volume hydrocarbon content along a section of a borehole.

Claim 56

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing an indication of a formation compaction factor which is representative of the compactness of a formation at the selected depth level; combining said third measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first, second, and third measurements to produce an indication of a formation characteristic at the selected depth level; testing said formation characteristic indication to determine if said characteristic indication is within a given limit; and adjusting said compaction factor indication if said formation characteristic indication is outside of said given limit and recombining said adjusted compaction factor indication with said third measurement to produce a new acoustic travel time derived porosity indication for recombination with said first and second measurements to produce a new indication of said formation characteristic at the selected depth level.

Claim 57

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing an indication of a formation compaction factor which is representative of the compactness of a formation at the selected depth level; combining said third measurement with said compaction factor indication to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first, second, and third measurements to produce an indication of a formation characteristic at the selected depth level; testing said formation characteristic indication to determine if said characteristic indication is within a given limit; and adjusting said compaction factor indication if said formation characteristic indication is outside of said given limit and recombining said adjusted compaction factor indication with said third measurement to produce a new acoustic travel time derived porosity indication for recombination with said first and second measurements to produce a new indication of said formation characteristic at the selected depth level.

Claim 58

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing indications of a formation compaction factor which is representative of the compactness of a formation and the acoustic travel time of a formation matrix at the selected depth level, said indications being previously ascertained from said first and second measurements obtained at various selected borehole depth levels; combining said indications with said third measurement to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce an indication of formation clay content at the selected depth level; testing said clay cOntent indication to determine if said clay content indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said clay content indication is outside of said given limit, said compaction factor indication being adjusted until reaching a given limit and thereafter adjusting said matrix travel time indication; and recombining said adjusted compaction factor and matrix travel time indications, if adjusted, with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements to produce a new indication of clay content at the selected depth level.

Claim 59

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing indications of a formation compaction factor which is representative of the compactness of a formation and the acoustic travel time of a formation matrix at the selected depth level, said indications being previously ascertained from said first and second measurements obtained at various selected borehole depth levels; combining said indications with said third measurement to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce an indication of formation clay content at the selected depth level; testing said clay cOntent indication to determine if said clay content indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said clay content indication is outside of said given limit, said compaction factor indication being adjusted until reaching a given limit and thereafter adjusting said matrix travel time indication; and recombining said adjusted compaction factor and matrix travel time indications, if adjusted, with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements to produce a new indication of clay content at the selected depth level.

Claim 60

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third porosity measurement functionally related to the acoustic travel time of a formation at the selected depth level; combining said first, second, and third measurements to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, total formation porosity, and effective, nonclay filled formation porosity at the selected depth level, each of said gas saturation, clay content, and effective and total porosity indications being functionally related to said derived porosity measurements; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total porosity to produce an indication of hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; and recording said gas and hydrocarbon saturation indications on a record medium to produce logs thereof whereby a comparison of said recorded logs will enable a determination of the relative oil and gas content of a formation.

Claim 61

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third porosity measurement functionally related to the acoustic travel time of a formation at the selected depth level; combining said first, second, and third measurements to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, total formation porosity, and effective, nonclay filled formation porosity at the selected depth level, each of said gas saturation, clay content, and effective and total porosity indications being functionally related to said derived porosity measurements; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total porosity to produce an indication of hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; and recording said gas and hydrocarbon saturation indications on a record medium to produce logs thereof whereby a comparison of said recorded logs will enable a determination of the relative oil and gas content of a formation.

Claim 62

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing an indication of a formation compaction factor which is representative of the compactness of a formation at the selected depth level, and an indication of the acoustic travel time of a formation matrix at the selected depth level; combining said third measurement with said formation compaction factor and matrix travel time indications to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, and total formation porosity at the selected depth level, each of said gas saturation, clay content, and total porosity indications being functionally related to said first and second measurements and travel time derived porosity and compaction factor indications; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total porosity to produce an indication of hydrocArbon saturation in said zone radially spaced from a borehole at the selected depth level; comparing said gas and hydrocarbon saturation indications to determine if said gas saturation indication is greater than a given percentage of said hydrocarbon saturation indication; adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is greater than said given percentage and recombining said third measurement with said compaction factor and matrix travel time indications to produce a new travel time derived porosity indication for recombination with said first, second, and fourth measurements to produce new indications of gas and hydrocarbon saturation at the selected depth level; and recording said new gas and hydrocarbon saturation indications on a record medium to produce logs thereof whereby a comparison of said recorded logs will enable a determination of the relative oil and gas content of a formation.

Claim 63

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing an indication of a formation compaction factor which is representative of the compactness of a formation at the selected depth level, and an indication of the acoustic travel time of a formation matrix at the selected depth level; combining said third measurement with said formation compaction factor and matrix travel time indications to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, and total formation porosity at the selected depth level, each of said gas saturation, clay content, and total porosity indications being functionally related to said first and second measurements and travel time derived porosity and compaction factor indications; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total porosity to produce an indication of hydrocArbon saturation in said zone radially spaced from a borehole at the selected depth level; comparing said gas and hydrocarbon saturation indications to determine if said gas saturation indication is greater than a given percentage of said hydrocarbon saturation indication; adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is greater than said given percentage and recombining said third measurement with said compaction factor and matrix travel time indications to produce a new travel time derived porosity indication for recombination with said first, second, and fourth measurements to produce new indications of gas and hydrocarbon saturation at the selected depth level; and recording said new gas and hydrocarbon saturation indications on a record medium to produce logs thereof whereby a comparison of said recorded logs will enable a determination of the relative oil and gas content of a formation.

Claim 64

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing an indication of a formation compaction factor which is representative of the compactness of a formation at the selected depth level, and an indication of the acoustic travel time of a formation rock matrix at the selected depth level; combining said third measurement with said formation compaction factor and matrix travel time indications to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time deriving porosity and compaction factor indications to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, and total formation porosity at the selected depth level, each of said gas saturation, clay content, and total porosity indications being functionally related to said first and second measurements and travel time derived porosity and compaction factor indications; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total porosity to produce an indication of hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is outside of said given limit and recombining said third measurement with said compaction factor and matrix travel time indication to produce a new travel time derived porosity indication for recombination with said first, second, and fourth measurements to produce new indications of gas and hydrocarbon saturation at the selected depth level; and recording said new gas and hydrocarbon saturation indications on a record medium to produce logs thereof whereby a comparison of the recorded logs will enable a determination of the relative oil and gas content of a formation.

Claim 65

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing an indication of a formation compaction factor which is representative of the compactness of a formation at the selected depth level, and an indication of the acoustic travel time of a formation rock matrix at the selected depth level; combining said third measurement with said formation compaction factor and matrix travel time indications to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time deriving porosity and compaction factor indications to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, and total formation porosity at the selected depth level, each of said gas saturation, clay content, and total porosity indications being functionally related to said first and second measurements and travel time derived porosity and compaction factor indications; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total porosity to produce an indication of hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said gas saturation indication is outside of said given limit and recombining said third measurement with said compaction factor and matrix travel time indication to produce a new travel time derived porosity indication for recombination with said first, second, and fourth measurements to produce new indications of gas and hydrocarbon saturation at the selected depth level; and recording said new gas and hydrocarbon saturation indications on a record medium to produce logs thereof whereby a comparison of the recorded logs will enable a determination of the relative oil and gas content of a formation.

Claim 66

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selEcted depth level; deriving a third porosity measurement functionally related to the acoustic travel time of a formation at the selected depth level; combining said first, second, and third measurements to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, total formation porosity, and effective, nonclay filled formation porosity at the selected depth level, each of said gas saturation, clay content and total and effective porosity indications being functionally related to said first, second and third measurements; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total and effective porosity to produce indications of that portion of the bulk volume of a formation filled with water and the hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level, each of said water and hydrocarbon saturation indications being functionally related to said fourth measurement and clay content, total and effective porosity indications; and recording said gas and hydrocarbon saturation indications on one track of a record medium to produce logs thereof whereby a comparison of said recorded logs will enable a determination of the relative oil and gas content of a formation, and recording said indications of bulk volume water and total and effective porosity on another track of said record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of the bulk volume clay content of a formation and the separation between said effective porosity and bulk volume water logs is indicative of the hydrocarbon saturation of a formation.

Claim 67

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selEcted depth level; deriving a third porosity measurement functionally related to the acoustic travel time of a formation at the selected depth level; combining said first, second, and third measurements to produce indications of formation gas saturation in a formation zone near a borehole, formation clay content, total formation porosity, and effective, nonclay filled formation porosity at the selected depth level, each of said gas saturation, clay content and total and effective porosity indications being functionally related to said first, second and third measurements; deriving a fourth measurement of the electrical resistivity of a formation zone radially spaced from a borehole at the selected depth level; combining said fourth measurement with said indications of formation clay content and total and effective porosity to produce indications of that portion of the bulk volume of a formation filled with water and the hydrocarbon saturation in said zone radially spaced from a borehole at the selected depth level, each of said water and hydrocarbon saturation indications being functionally related to said fourth measurement and clay content, total and effective porosity indications; and recording said gas and hydrocarbon saturation indications on one track of a record medium to produce logs thereof whereby a comparison of said recorded logs will enable a determination of the relative oil and gas content of a formation, and recording said indications of bulk volume water and total and effective porosity on another track of said record medium to produce logs thereof whereby the separation between said total and effective porosity logs is indicative of the bulk volume clay content of a formation and the separation between said effective porosity and bulk volume water logs is indicative of the hydrocarbon saturation of a formation.

Claim 68

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing indications of a formation compaction factor which is representative of the compactness of a formation at the selected depth level and the acoustic travel time of a formation matrix at the selected depth level, said indications being previously ascertained from said first and second measurements obtained at various selected borehole depth levels; combining said indications with said third measurement to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce indications of formation clay content and gas saturation at the selected depth level, each of said clay content and gas saturation indications being functionally related to said first and second measurements and said travel time derived porosity and compaction factor indications; testing said clay content and gas saturation indications to determine if said clay content and gas saturation indications are within given limits; adjusting one of said compaction factor or matrix travel time indications if either of said clay content or gas saturation indications are outside of said given limit, said compaction factor indication being adjusted until reaching a given limit and thereafter adjusting said matrix travel time indication; and recombining said adjusted compaction factor and matrix travel time indications with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements To produce new indications of clay content and gas saturation at the selected depth level.

Claim 69

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing indications of a formation compaction factor which is representative of the compactness of a formation at the selected depth level and the acoustic travel time of a formation matrix at the selected depth level, said indications being previously ascertained from said first and second measurements obtained at various selected borehole depth levels; combining said indications with said third measurement to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce indications of formation clay content and gas saturation at the selected depth level, each of said clay content and gas saturation indications being functionally related to said first and second measurements and said travel time derived porosity and compaction factor indications; testing said clay content and gas saturation indications to determine if said clay content and gas saturation indications are within given limits; adjusting one of said compaction factor or matrix travel time indications if either of said clay content or gas saturation indications are outside of said given limit, said compaction factor indication being adjusted until reaching a given limit and thereafter adjusting said matrix travel time indication; and recombining said adjusted compaction factor and matrix travel time indications with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements To produce new indications of clay content and gas saturation at the selected depth level.

Claim 70

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing indications of a formation compaction factor which is representative of the compactness of a formation at the selected depth level and the acoustic travel time of a formation matrix at the selected depth level, said indications being previously ascertained from said first and second measurements obtained at various selected borehole depth levels; combining said indications with said third measurement to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce indications of formation clay content and gas saturation at the selected depth level, each of said clay content and gas saturation indications being functionally related to said first and second measurements and said travel time derived porosity and compaction factor indications; testing said clay content indication to determine if said clay content indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said clay content indication is outside of said given limit, said compaction factor indication being adjusted until reaching a given limit and thereafter adjusting said matrix travel time indication; recombining said adjusted compaction factor and matrix travel time indications, if adjusted, with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements to produce new indications of clay content and gas saturation at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; adjusting one of said compaction factor or matrix travel indications if said gas saturation indication is outside of said given limit unless said last named adjustment will cause said new clay content indication to be outside of its given limit; and recombining said adjusted compaction factor and matrix travel time indications with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements to produce new clay content and gas saturation at the selected depth level.

Claim 71

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving a first porosity measurement functionally related to formation hydrogen content at a selected borehole depth level; deriving a second porosity measurement functionally related to formation bulk density at the selected depth level; deriving a third measurement representative of the acoustic travel time of a formation at the selected depth level; providing indications of a formation compaction factor which is representative of the compactness of a formation at the selected depth level and the acoustic travel time of a formation matrix at the selected depth level, said indications being previously ascertained from said first and second measurements obtained at various selected borehole depth levels; combining said indications with said third measurement to produce an indication of acoustic travel time derived porosity at the selected depth level; combining said first and second measurements with said travel time derived porosity and compaction factor indications to produce indications of formation clay content and gas saturation at the selected depth level, each of said clay content and gas saturation indications being functionally related to said first and second measurements and said travel time derived porosity and compaction factor indications; testing said clay content indication to determine if said clay content indication is within a given limit; adjusting one of said compaction factor or matrix travel time indications if said clay content indication is outside of said given limit, said compaction factor indication being adjusted until reaching a given limit and thereafter adjusting said matrix travel time indication; recombining said adjusted compaction factor and matrix travel time indications, if adjusted, with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements to produce new indications of clay content and gas saturation at the selected depth level; testing said gas saturation indication to determine if said gas saturation indication is within a given limit; adjusting one of said compaction factor or matrix travel indications if said gas saturation indication is outside of said given limit unless said last named adjustment will cause said new clay content indication to be outside of its given limit; and recombining said adjusted compaction factor and matrix travel time indications with said measured travel time to produce a new travel time derived porosity indication for recombination with said first and second measurements to produce new clay content and gas saturation at the selected depth level.

Claim 72

A method of processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; deriving third measurements functionally related to one of the naturally occurring electrical potential or radioactivity of a formation and using said third measurements to determine the relative amount of clay in a formation to produce a representation of such clay content; combining said first and second measurements to produce values of formation clay content along the borehole section; and utilizing said clay content representation derived from said third measurement to inhibit the combination of said first and second measurements if said third measurement exceeds a given limit.

Claim 73

A method of processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; deriving third measurements functionally related to one of the naturally occurring electrical potential or radioactivity of a formation and using said third measurements to determine the relative amount of clay in a formation to produce a representation of such clay content; combining said first and second measurements to produce values of formation clay content along the borehole section; and utilizing said clay content representation derived from said third measurement to inhibit the combination of said first and second measurements if said third measurement exceeds a given limit.

Claim 74

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; deriving third measurements functionally related to the resistivity of the noninvaded zone of the formation over the borehole section; combining said first, second and third derived measurements to compute output representations functionally related to one or more of the shale or clay content, porosity, invaded zone water or gas saturation, or noninvaded zone water or hydrocarbon saturation; comparing one or more of said output representations with each other or predetermined limit values to determine feasibility of said compared output representations and computing one or more of said parameters given by said output representations if said compared output representations are not feasible.

Claim 75

A method of machine processing well logging data derived from exploring devices which investigate earth formations traversed by a borehole, comprising: deriving first porosity measurements functionally related to formation hydrogen content along a section of a borehole traversing earth formations; deriving second measurements functionally related to formation bulk density along the section of a borehole; deriving third measurements functionally related to the resistivity of the noninvaded zone of the formation over the borehole section; combining said first, second and third derived measurements to compute output representations functionally related to one or more of the shale or clay content, porosity, invaded zone water or gas saturation, or noninvaded zone water or hydrocarbon saturation; comparing one or more of said output representations with each other or predetermined limit values to determine feasibility of said compared output representations and computing one or more of said parameters given by said output representations if said compared output representations are not feasible.