Patent US3620303A successfully refreshed from Google Patents.
US3620303A
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Tar recovery method
Assignee: Tenneco Oil Co
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Filing: 1970-01-15
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Granted: 1971-11-16
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Expires: 1990-01-15
Abstract
Abstract A method for recovering tar or extremely viscous hydrocarbons from an underground formation. The method includes the steps of injecting an aqueous solution of anionic orthophosphate ester surfactant into the hydrocarbon-bearing formation, retaining the surfactant in the formation at least about 24 hours, and displacing the solubilized hydrocarbon toward a recovery well. The surfactant solution forms a soluble oil microemulsion with the formation hydrocarbons.
Inventors
- 👤 William G Halbert Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:47
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/584; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
31 words
The invention as claimed in claim 1 wherein: the size of said slug of aqueous surfactant is about 2 percent to about 25 percent of the pore volume of the formation.
Claim 2
Dependent Claim
28 words
The invention as claimed in claim 1 wherein: said injection step includes the further step of steam-soaking during said injection and retention of said surfactant into said formation.
Claim 3
Dependent Claim
29 words
The invention as claimed in claim 1 wherein: said surfactant solution includes sufficient sodium hydroxide to elevate the pH of said solution to a value greater than about 7.0.
Claim 4
Dependent Claim
30 words
The invention as claimed in claim 1 wherein: said surfactant solution includes a concentration of said surfactant in water of greater than about 3 to about 10 percent by volume.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |