US3409083A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Petroleum recovery by thermal backflow
Assignee: Shell USA Inc
•
Filing: 1967-06-09
•
Granted: 1968-11-05
•
Expires: 1987-06-09
Abstract
No abstract record available.
Inventors
- 👤 Prats Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:17
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/243
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3129757A
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US3139928A
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US3171482A
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US3259186A
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US3285336A
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US3330353A
Cited
US3332482A
Cited
US3292702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-11-05 | 1972-05-06 | 1972-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-11-05 | 1976-05-06 | 1976-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-11-05 | 1980-05-06 | 1980-11-05 | $7700.00 | Window Closed / Lapsed |