Patent US3328679A successfully refreshed from Google Patents.
US3328679A
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Electromagnetic well logging systems with means for modulating the detected signals
Assignee: Schlumberger Technology Corp
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Filing: 1964-11-13
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Granted: 1967-06-27
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Expires: 1984-11-13
Abstract
No abstract record available.
Inventors
- 👤 William J Sloughter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:50
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/26; G01V3/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
93 words
IN APPARATUS FOR INVESTIGATING AN ELECTRICAL PROPERTY OF EARTH FORMATIONS TRANVERSED BY A BOREHOLE, THE COMBINATION COMPRISING A TRANSMITTER AND A RECEIVER COIL SPACED FOR LONGITUDINAL MOVEMENT THROUGH A BOREHOLE, MEANS FOR ENERGIZING SAID TRANSMITTER COIL TO INDUCE IN SAID RECEIVER COIL A SIGNAL HAVING A COMPONENT DEPENDENT UPON THE CONDUCTIVITY OF ADJACENT FORMATIONS, PHASE SENSITIVE DETECTING MEANS RESPONSIVE TO SAID SIGNAL COMPONENT FOR PRODUCING A MEASURE SIGNAL REPRESENTING FORMATION CONDUCTIVITY, MEANS FOR MODULATING THE AMPLITUDE OF SAID SIGNAL COMPONENT PERIODICALLY TO VARY SAID MEASURE SIGNAL AND THEREBY IMPART A READILY INDENTIFIABLE CHARAC-
Claim 2
Dependent Claim
93 words
IN APPARATUS FOR INVESTIGATING AN ELECTRICAL PROPERTY OF EARTH FORMATIONS TRANVERSED BY A BOREHOLE, THE COMBINATION COMPRISING A TRANSMITTER AND A RECEIVER COIL SPACED FOR LONGITUDINAL MOVEMENT THROUGH A BOREHOLE, MEANS FOR ENERGIZING SAID TRANSMITTER COIL TO INDUCE IN SAID RECEIVER COIL A SIGNAL HAVING A COMPONENT DEPENDENT UPON THE CONDUCTIVITY OF ADJACENT FORMATIONS, PHASE SENSITIVE DETECTING MEANS RESPONSIVE TO SAID SIGNAL COMPONENT FOR PRODUCING A MEASURE SIGNAL REPRESENTING FORMATION CONDUCTIVITY, MEANS FOR MODULATING THE AMPLITUDE OF SAID SIGNAL COMPONENT PERIODICALLY TO VARY SAID MEASURE SIGNAL AND THEREBY IMPART A READILY INDENTIFIABLE CHARAC-
References Cited (Backward Citations)
US2220788A
Cited
US2220070A
Cited
US2415364A
Cited
US2451596A
Cited
US2573133A
Cited
US2582314A
Cited
US2712609A
Cited
US2782364A
Cited
US2723375A
Cited
US3052835A
Cited
US2884589A
Cited
US2880389A
Cited
US2790138A
Cited
US2928038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-06-26 | 1970-12-26 | 1971-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-06-26 | 1974-12-26 | 1975-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-06-26 | 1978-12-26 | 1979-06-27 | $7700.00 | Window Closed / Lapsed |