Patent US3500916A successfully refreshed from Google Patents.
US3500916A
Expired / Lapsed
US
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Method of recovering crude oil from a subsurface formation
Assignee: Shell USA Inc
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Filing: 1968-10-03
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Granted: 1970-03-17
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Expires: 1988-10-03
Abstract
No abstract record available.
Inventors
- 👤 Willem Van Der Knaap
- 👤 Francois Van Daalen
- 👤 Florian Lehner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:38
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/20; C; C09; C09K; C09K8/00; C09K8/58
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2669307A
Cited
US2862558A
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US3065790A
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US3215197A
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US3270809A
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US3376925A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-16 | 1973-09-15 | 1974-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-16 | 1977-09-15 | 1978-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-16 | 1981-09-15 | 1982-03-17 | $7700.00 | Window Closed / Lapsed |