US2725523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple coil apparatus for induction well logging
Assignee: Schlumberger Well Surveying Corp
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Filing: 1952-06-06
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Granted: 1955-11-29
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Expires: 1972-06-06
Abstract
No abstract record available.
Inventors
- 👤 Doll Henri-Georges
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:35
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/26; G01V3/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
IN APPARATUS FOR INVESTIGATING EARTH FORMATIONS TRAVERSED BY A BORE HOLE, THE COMBINATION OF AN ELONGATED CORE ADAPTED TO BE LOWERED INTO THE BORE HOLE, FIRST AND SECOND COILS SUPPORTED BY SAID CORE IN CLOSE INDUCTIVE COUPLING RELATION, MEANS FOR ENERGIZING ONE OF SAID COILS WITH ALTERNATING CURRENT OF SUBSTANTIALLY CONSTANT MAGNITUDE, AND MEANS RESPONSIVE TO THE SIGNAL INDUCED IN THE OTHER OF SAID COILS FOR INDICATING A CHARACTERISTIC OF THE EARTH FORMATIONS.
Claim 2
Dependent Claim
73 words
IN APPARATUS FOR INVESTIGATING EARTH FORMATIONS TRAVERSED BY A BORE HOLE, THE COMBINATION OF AN ELONGATED CORE ADAPTED TO BE LOWERED INTO THE BORE HOLE, FIRST AND SECOND COILS SUPPORTED BY SAID CORE IN CLOSE INDUCTIVE COUPLING RELATION, MEANS FOR ENERGIZING ONE OF SAID COILS WITH ALTERNATING CURRENT OF SUBSTANTIALLY CONSTANT MAGNITUDE, AND MEANS RESPONSIVE TO THE SIGNAL INDUCED IN THE OTHER OF SAID COILS FOR INDICATING A CHARACTERISTIC OF THE EARTH FORMATIONS.
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 |