US3368636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of drilling a hole in a permeable underground formation and drilling fluid suitable for carrying out said method
Assignee: Shell USA Inc
•
Filing: 1964-11-30
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Granted: 1968-02-13
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Expires: 1984-11-30
Abstract
No abstract record available.
Inventors
- 👤 Jongbloed Lodewijk J Schmit
- 👤 Nicolaas H Van Lingen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:08
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24; E; E21; E21B; E21B21/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2259875A
Cited
US2380156A
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US2812161A
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US3040822A
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US3223185A
Cited
US3221825A
Cited
US3158210A
Cited
US3228469A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-02-12 | 1971-08-14 | 1972-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-02-12 | 1975-08-14 | 1976-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-02-12 | 1979-08-14 | 1980-02-13 | $7700.00 | Window Closed / Lapsed |