US3504745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of foams to prevent vertical flow in tar sands during in-situ combustion
Assignee: Pan American Petroleum Corp
•
Filing: 1968-05-08
•
Granted: 1970-04-07
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Expires: 1988-05-08
Abstract
No abstract record available.
Inventors
- 👤 Lloyd E Elkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:39
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/14; E21B43/00; E21B43/16; E21B43/24; E21B43/243
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3221813A
Cited
US3369601A
Cited
US3349843A
Cited
US3366175A
Cited
US3372750A
Cited
US3410344A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-04-06 | 1973-10-06 | 1974-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-04-06 | 1977-10-06 | 1978-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-04-06 | 1981-10-06 | 1982-04-07 | $7700.00 | Window Closed / Lapsed |