Patent EP0206593A1 successfully refreshed from Google Patents.
EP0206593A1
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EP
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Borehole compensation method and apparatus
Assignee: Halliburton Co
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Filing: 1986-06-05
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Granted: —
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Expires: 2006-06-05
Abstract
Abstract Compensation of photoelectric absorption measurements for borehole effects during nuclear logging of downhole earth formations is accomplished in a method and apparatus of the invention by detecting low energy gamma radiations entering two detectors (22, 23) in the logging tool apparatus along paths having substantially constant formation components but varying borehole components.
Inventors
- 👤 Ward Edward Schultz
- 👤 Harry Davis Smith, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 15:15
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/12; G01V5/125
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
132 words
A method for compensating for borehole effects in logging downhole earth formations, which method comprises: a) measuring, with a first detector within the borehole, a predetermined radiation entering the borehole along a first predetermined path, and generating a first signal representative of the radiation so measured, b) measuring, with a second detector within the borehole, predetermined radiation of the same kind entering the borehole along a second predetermined path different from the first path, and generating a second signal representative of the radiation so measured, c) selecting said predetermined first and second paths such that differences in the relative formation components of said first and second signals are minimized, and the relative borehole components thereof are varied, and - d) determining, as a predetermined function of said signals, the borehole effects thereon.
Claim 2
Independent Claim
132 words
A method for compensating for borehole effects in logging downhole earth formations, which method comprises: a) measuring, with a first detector within the borehole, a predetermined radiation entering the borehole along a first predetermined path, and generating a first signal representative of the radiation so measured, b) measuring, with a second detector within the borehole, predetermined radiation of the same kind entering the borehole along a second predetermined path different from the first path, and generating a second signal representative of the radiation so measured, c) selecting said predetermined first and second paths such that differences in the relative formation components of said first and second signals are minimized, and the relative borehole components thereof are varied, and - d) determining, as a predetermined function of said signals, the borehole effects thereon.
Claim 3
Dependent Claim
20 words
A method according to claim 1, further comprising compensating at least one of said signals for the borehole effects thereon.
Claim 4
Dependent Claim
26 words
A method according to claim 1 or 2, wherein said steps of measuring such predetermined radiation further comprise detecting low energy photoelectrically sensitive scattered gamma radiation.
Claim 5
Dependent Claim
49 words
A method according to claim 3, wherein said steps of detecting low energy scattered gamma radiation each further comprise detecting low energy scattered gamma radiation having a substantially isotropic distribution substantially equivalent to a photoelectric source located in a volume of the formation substantially adjacent the respective said detector.
Claim 6
Dependent Claim
38 words
A method according to claim 1,2,3 or 4, further comprising physically varying the relative borehole path lengths along the first and second paths, while the effective formation signals for the first and second detectors remains substantially the same.
Claim 7
Dependent Claim
35 words
A method according to claim 5, wherein said step of physically varying the relative"borehole path lengths along the first and second paths further comprises measuring the radiations using different effective aperture widths in the detectors.
Claim 8
Independent Claim
26 words
A method according to any of claims 1 to 6, further comprising deriving from said signals a measure of the photoelectric absorption properties of the formation.
Claim 9
Dependent Claim
138 words
Apparatus for logging downhole earth formations penetrated by a borehole and compensating for borehole effects, comprising: a) a first detector (22) for measuring within the borehole a predetermined radiation entering the borehole along a first predetermined path, and generating a first signal representative of the radiation so measured, b) a second detector (23) for measuring within the borehole predetermined radiation of the same kind entering the borehole along a second predetermined path different from said first path, and generating a second signal representative of the radiation so measured, c) means for selecting said predetermined first and second paths such that the relative formation components of said first and second signals are held substantially constant and the relative borehole components thereof are varied, and d) means for determining, as a predetermined function of said signals, the borehole effects thereon.
Claim 10
Dependent Claim
138 words
Apparatus for logging downhole earth formations penetrated by a borehole and compensating for borehole effects, comprising: a) a first detector (22) for measuring within the borehole a predetermined radiation entering the borehole along a first predetermined path, and generating a first signal representative of the radiation so measured, b) a second detector (23) for measuring within the borehole predetermined radiation of the same kind entering the borehole along a second predetermined path different from said first path, and generating a second signal representative of the radiation so measured, c) means for selecting said predetermined first and second paths such that the relative formation components of said first and second signals are held substantially constant and the relative borehole components thereof are varied, and d) means for determining, as a predetermined function of said signals, the borehole effects thereon.
Claim 11
Dependent Claim
21 words
Apparatus according to claim 8, further comprising means for compensating at least one of said signals for the borehole effects thereon.
Claim 12
Dependent Claim
22 words
Apparatus according to claim 8 or 9, wherein said detectors further comprise detectors for detecting low energy photoelectrically sensitive scattered gamma radiation.
References Cited (Backward Citations)
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