Patent US3706884A successfully refreshed from Google Patents.
US3706884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulsed neutron well logging apparatus having for determing background radiation
Assignee: Western Atlas International Inc
•
Filing: 1967-06-30
•
Granted: 1972-12-19
•
Expires: 1987-06-30
Abstract
Abstract Three gates provide means for eliminating the radiation background count in pulsed neutron well logging. Circuitry provides the determination of the extrapolated counting rate at time zero.
Inventors
- 👤 Arthur H Youmans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:30
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/10; G01V5/101; G01V5/102
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A system for radioactivity well logging comprising a source of neutrons, radiation detection means in a spaced relationship to said source, said detection system including at least a first and second gate, means for causing said source to produce a discrete burst of neutrons and for triggering said gates to provide an indication functionally representative of the rate of decline of at least a portion of said neutrons in a medium, means for combining the outputs of said gates to provide a signal directly proportional to the neutron counting rate at time zero following said neutron burst, and means for recording said indication of the neutron counting rate as a function of depth within the well.
Claim 2
Independent Claim
116 words
A system for radioactivity well logging comprising a source of neutrons, radiation detection means in a spaced relationship to said source, said detection system including at least a first and second gate, means for causing said source to produce a discrete burst of neutrons and for triggering said gates to provide an indication functionally representative of the rate of decline of at least a portion of said neutrons in a medium, means for combining the outputs of said gates to provide a signal directly proportional to the neutron counting rate at time zero following said neutron burst, and means for recording said indication of the neutron counting rate as a function of depth within the well.
Claim 3
Dependent Claim
31 words
The system according to claim 1 including means for recording said indication of the rate of decline of the neutrons within a medium as a function of depth within a well.
Claim 4
Dependent Claim
45 words
The system according to claim 1, including neutron source monitoring means connected to said means for combining the outputs of said gates, wherein said indication of the neutron counting rate at time zero is recorded as a function of the strength of said neutron burst.
Claim 5
Dependent Claim
89 words
The system according to claim 1, wherein said means for combining the outputs of said gates to provide an indication of the neutron counting rate at time zero comprises circuitry for solving the equation for No, wherein where No the neutron counting rate at time zero, N1 the first gate counting rate, N2 the second gate counting rate, Sigma the thermal neutron capture cross section, V velocity of neutrons, To starting time of the first Gate after time zero plus the gate width, and a spacing between the gates.
Claim 6
Dependent Claim
72 words
The system according to claim 1 wherein said means for combining the outputs of said gates to provide an indication of the neutron counting rate at time zero comprises circuitry for solving the equation for No, wherein No (N12/N2) . (1/M) wherein No the neutron counting rate at time zero, N1 the first gate counting rate, N2 the second gate counting rate, and M is a function of the neutron burst strength.
References Cited (Backward Citations)
US3566116A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |