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US3374341A
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Method for controlling pressure differential resulting from fluid friction forces in well-drilling operations
Assignee: Union Oil Company of California
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Filing: 1963-11-26
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Granted: 1968-03-19
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Expires: 1983-11-26
Abstract
No abstract record available.
Inventors
- 👤 James A Klotz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:30
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/06
Claims Analysis
Total Claims: 0
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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) | 1971-03-19 | 1971-09-18 | 1972-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-03-19 | 1975-09-18 | 1976-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-03-19 | 1979-09-18 | 1980-03-19 | $7700.00 | Window Closed / Lapsed |