Patent US2551768A successfully refreshed from Google Patents.
US2551768A
Expired / Lapsed
US
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Rotary drilling fluids
Assignee: Union Oil Company of California
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Filing: 1947-10-24
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Granted: 1951-05-08
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Expires: 1967-10-24
Abstract
No abstract record available.
Inventors
- 👤 John E Sherborne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:01
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/20; C09K8/206
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
41 words
A DRILLING FLUID FOR THE DRILLING OF OIL, GAS AND WATER WELLS WHICH COMPRISES A MUD OF WHICH HAS BEEN ADDED BETWEEN ABOUT 4 AND 6 POUNDS PER BARREL OF CALCIUM CHLORIDE AND ABOUT 10 POUNDS PER BARREL OF GELATINIZED STARCH.
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) | 1954-05-07 | 1954-11-06 | 1955-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-05-07 | 1958-11-06 | 1959-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-05-07 | 1962-11-06 | 1963-05-08 | $7700.00 | Window Closed / Lapsed |