Patent US3448807A successfully refreshed from Google Patents.
US3448807A
Expired / Lapsed
US
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Process for the thermal recovery of hydrocarbons from an underground formation
Assignee: Shell USA Inc
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Filing: 1967-12-08
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Granted: 1969-06-10
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Expires: 1987-12-08
Abstract
No abstract record available.
Inventors
- 👤 William T Strickland Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:56
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)
US3150715A
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US3208519A
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US3171479A
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US3196945A
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US3182721A
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US3208516A
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US3269460A
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US3204694A
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US3369601A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-09 | 1972-12-09 | 1973-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-09 | 1976-12-09 | 1977-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-09 | 1980-12-09 | 1981-06-10 | $7700.00 | Window Closed / Lapsed |