US3478825A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of increasing the volume of a permeable zone within an oil shale formation
Assignee: Shell USA Inc
•
Filing: 1967-08-21
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Granted: 1969-11-18
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Expires: 1987-08-21
Abstract
No abstract record available.
Inventors
- 👤 Philip J Closmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:07
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/263; E21B43/2635
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2813583A
Cited
US3113620A
Cited
US3180414A
Cited
US3303881A
Cited
US3285335A
Cited
US3273640A
Cited
US3342257A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-11-17 | 1973-05-19 | 1973-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-11-17 | 1977-05-19 | 1977-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-11-17 | 1981-05-19 | 1981-11-18 | $7700.00 | Window Closed / Lapsed |