US2725486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for well logging
Assignee: California Research LLC
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Filing: 1952-12-09
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Granted: 1955-11-29
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Expires: 1972-12-09
Abstract
No abstract record available.
Inventors
- 👤 John E Walstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:20
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/12
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
113 words
A WELL BORE LOGGING TOOL COMPRISING MEANS FOR DETECTING RADIOACTIVITY POSITIONED IN SAID TOOL, A PLURALITY OF SOURCE OF RADIOACTIVITY MOVABLE WITH RESPECT TO SAID DETECTING MEANS, A PLURALITY OF MEANS FOR ENGAGING THE WALLS OF A BOREHOLE, EACH OF SAID PLURALITY OF RADIOACTIVE SOURCE BEING MOVABLE RELATIVE TO SAID DETECTOR IN ACCORDANCE WITH THE LATERAL DISPLACEMENT OF ONE OF SAID PLURALITY OF WALL-ENGAGING MEANS WHEN SAID MEANS ARE IN ENGAGEMENT WITH THE WALLS OF SAID BOREHOLE, AND MEANS FOR CORRELATING THE INTENSITY OF RADIOACTIVITY MEASURED BY SAID DETECTING MEANS WITH THE DEPTH OF SAID TOOL IN SAID WELL BORE AS A MEASUREMENT OF CHANGES IN THE CROSS-SECTIONAL AREA OF SAID WELL BORE.
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) | 1958-11-28 | 1959-05-30 | 1959-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-11-28 | 1963-05-30 | 1963-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-11-28 | 1967-05-30 | 1967-11-29 | $7700.00 | Window Closed / Lapsed |