Patent US5170789A successfully refreshed from Google Patents.
US3343601A
Expired / Lapsed
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Water flooding process
Assignee: Dow Chemical Co
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Filing: 1965-09-17
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Granted: 1967-09-26
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Expires: 1985-09-17
Abstract
No abstract record available.
Inventors
- 👤 David J Pye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:54
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/20; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
48 words
IN A PROCESS FOR THE SECONDARY RECOVERY OF OIL WHICH COMPRISES INJECTING AN AQUEOUS FLUID CONTAINING A DISPERSED IRON COMPOUND INTO AN OIL-BEARING FORMATION, THE IMPROVEMENT WHICH COMPRISES INCORPORATING INTO THE INJECTION FLUID A WATER-SOLUBLE, HYDROSULFITE IN AN AMOUNT SUFFICIENT TO PREVENT FERRIC HYDROXIDE PLUGGING OF THE FORMATION.
Claim 2
Dependent Claim
48 words
IN A PROCESS FOR THE SECONDARY RECOVERY OF OIL WHICH COMPRISES INJECTING AN AQUEOUS FLUID CONTAINING A DISPERSED IRON COMPOUND INTO AN OIL-BEARING FORMATION, THE IMPROVEMENT WHICH COMPRISES INCORPORATING INTO THE INJECTION FLUID A WATER-SOLUBLE, HYDROSULFITE IN AN AMOUNT SUFFICIENT TO PREVENT FERRIC HYDROXIDE PLUGGING OF THE FORMATION.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-25 | 1971-03-27 | 1971-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-25 | 1975-03-27 | 1975-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-25 | 1979-03-27 | 1979-09-26 | $7700.00 | Window Closed / Lapsed |