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US2152306A
Expired / Lapsed
US
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Method of removing metal obstructions from wells
Assignee: Dow Chemical Co
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Filing: 1936-09-30
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Granted: 1939-03-28
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Expires: 1956-09-30
Abstract
No abstract record available.
Inventors
- 👤 John J Grebe
- 👤 Sylvia M Stoesser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:50
CPC Classifications
E; E21; E21B; E21B31/00; E21B31/002; C; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S507/00; Y10S507/933; Y10S507/94
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1942-03-27 | 1942-09-26 | 1943-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-03-27 | 1946-09-26 | 1947-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-03-27 | 1950-09-26 | 1951-03-28 | $7700.00 | Window Closed / Lapsed |