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US2852091A
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Separating means for aerated mud drilling
Assignee: Phillips Petroleum Co
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Filing: 1957-04-03
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Granted: 1958-09-16
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Expires: 1977-04-03
Abstract
No abstract record available.
Inventors
- 👤 George S Boudreaux
- 👤 Robert S Hoch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:02
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/06; E21B21/063; E21B21/067
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) | 1961-09-15 | 1962-03-17 | 1962-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-15 | 1966-03-17 | 1966-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-15 | 1970-03-17 | 1970-09-16 | $7700.00 | Window Closed / Lapsed |