US3515214A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical waterflooding techniques using complex surfactants
Assignee: Shell USA Inc
•
Filing: 1968-04-17
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Granted: 1970-06-02
•
Expires: 1988-04-17
Abstract
No abstract record available.
Inventors
- 👤 Harry D Finch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:59
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/584
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3391736A
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US3330344A
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US3292698A
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US3315744A
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US3348611A
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US3373809A
Cited
US3407877A
Cited
US3406754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-06-01 | 1973-12-01 | 1974-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-01 | 1977-12-01 | 1978-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-01 | 1981-12-01 | 1982-06-02 | $7700.00 | Window Closed / Lapsed |