Patent US3829686A successfully refreshed from Google Patents.
US3829686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulsed neutron logging system with gain compensation
Assignee: Texaco Inc
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Filing: 1973-06-28
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Granted: 1974-08-13
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Expires: 1993-06-28
Abstract
Abstract An illustrative embodiment of the invention includes method and apparatus for linearizing the gain of borehole gamma ray energy measurement apparatus. A known energy peak (or peaks) which is prominent in the gamma ray energy spectra of borehole measurements is monitored and any drift in its apparent location in the energy spectrum is used to generate an error voltage. The error voltage is applied in an inverse feedback manner to control the gain of system amplifiers to cancel the drift.
Inventors
- 👤 W Schultz
- 👤 H Smith
- 👤 D Arnold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:33
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/10; G01V5/101; G01V5/102
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
120 words
A method for controlling and linearizing the gain of a nuclear well logging system comprising the steps of: measuring the energy spectrum of gamma rays produced by earth formation materials surrounding a well borehole with digital energy measurement equipment having sufficient resolution to discern at least one recognizable energy peak in said gamma ray energy spectrum, said peak being the 2.22 MEV hydrogen photopeak; comparing the apparent location of said 2.22 MEV hydrogen peak in said spectrum with its known location and generating an error signal proportional to the difference between its known location and its apparent location; and controlling the gain of said energy measurement equipment in response to said error signal so as to minimize said error signal.
Claim 2
Independent Claim
120 words
A method for controlling and linearizing the gain of a nuclear well logging system comprising the steps of: measuring the energy spectrum of gamma rays produced by earth formation materials surrounding a well borehole with digital energy measurement equipment having sufficient resolution to discern at least one recognizable energy peak in said gamma ray energy spectrum, said peak being the 2.22 MEV hydrogen photopeak; comparing the apparent location of said 2.22 MEV hydrogen peak in said spectrum with its known location and generating an error signal proportional to the difference between its known location and its apparent location; and controlling the gain of said energy measurement equipment in response to said error signal so as to minimize said error signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |