Patent US2674440A successfully refreshed from Google Patents.
US2674440A
Expired / Lapsed
US
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Process for drilling wells, including dialysis of the drilling mud
Assignee: Phillips Petroleum Co
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Filing: 1951-02-26
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Granted: 1954-04-06
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Expires: 1971-02-26
Abstract
No abstract record available.
Inventors
- 👤 Harry T Donovan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:20
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/06; E21B21/063; E21B21/065; B; B01; B01D; B01D61/00; B01D61/24; B01D61/243
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1825631A
Cited
US2156333A
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US2218533A
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US2571247A
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US2366184A
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US2502614A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-04-05 | 1957-10-05 | 1958-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-04-05 | 1961-10-05 | 1962-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-04-05 | 1965-10-05 | 1966-04-06 | $7700.00 | Window Closed / Lapsed |