US2986639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Groundwater direction determination
Assignee: Union Oil Company of California
•
Filing: 1957-04-25
•
Granted: 1961-05-30
•
Expires: 1977-04-25
Abstract
No abstract record available.
Inventors
- 👤 Virgil A Josendal
- 👤 Richard J Stegemeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:24
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/08; E21B49/087; E21B47/00; E21B47/10; E21B47/11
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2433718A
Cited
US2856536A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-05-29 | 1964-11-28 | 1965-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-05-29 | 1968-11-28 | 1969-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-05-29 | 1972-11-28 | 1973-05-30 | $7700.00 | Window Closed / Lapsed |