US3562526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Neutron-gamma ray well logging apparatus employing spaced gamma ray detectors
Assignee: Phillips Petroleum Co
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Filing: 1967-10-17
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Granted: 1971-02-09
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Expires: 1987-10-17
Abstract
Abstract A neutron-gamma ray well-logging device comprises a neutron source and two spaced gamma ray detectors. The detectors are shielded so that only gamma rays which emerge from the formations at a predetermined angle are allowed to strike the first detector. Only gamma rays which are emitted from the first detector at a predetermined angle are allowed to strike the second detector.
Inventors
- 👤 Bobby L Lawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:15
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/10; G01V5/101
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
101 words
The apparatus of claim 1 wherein said first gamma ray detector comprises a first scintillation crystal positioned at said first location, and a first photomultiplier tube positioned adjacent said first crystal to receive light flashes therefrom; and said second gamma ray detector comprises a second scintillation crystal positioned at said second location, and a second photomultiplier tube positioned adjacent said first crystal to receive light flashes therefrom, said tubes being positioned with respect to said crystals so that said first tube receives light flashes only from said first crystal and said second tube receives light flashes only from said second crystal.
Claim 2
Dependent Claim
87 words
The apparatus of claim 2 wherein said shielding means are constructed of lead. 4. The apparatus of claim 2 wherein said first shielding means is provided with a plurality of first straight passages which extend outwardly from said first crystal at said first angle, and said second shielding means is provided with a plurality of second straight passages which are parallel with one another and which extend from said first crystal to said second crystal at said second angle, said passages permitting passage of gamma rays therethrough.
Claim 3
Dependent Claim
17 words
The apparatus of claim 4 wherein the angle between said first and second passages is approximately 83.5*.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2, further comprising a thermal neutron shield enclosing said first and second detectors.
Claim 5
Dependent Claim
123 words
The apparatus of claim 2 further comprising: first, second and third pulse height analyzers; a coincidence circuit; a gate circuit; a recorder; means connecting the outputs of said first and second Photomultiplier tubes to the inputs of said first and second analyzers, respectively; means connecting the outputs of said first and second analyzers to the inputs of said coincidence circuit; means connecting the output of said first analyzer to the input of said gate circuit; means to control opening of said gate circuit in response to the output of said coincidence circuit; means connecting the output of said gate circuit to the input of said third pulse height analyzer; and means connecting the output of said third pulse height analyzer to said recorder.
Claim 6
Dependent Claim
28 words
The apparatus of claim 7 wherein said second pulse height analyzer is set to pass only signals representative of detected gamma rays having energies of approximately 0.51 Mev.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |