Patent US3777818A successfully refreshed from Google Patents.
US3777818A
Expired / Lapsed
US
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Oil recovery process
Assignee: Texaco Inc
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Filing: 1971-12-30
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Granted: 1973-12-11
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Expires: 1991-12-30
Abstract
Abstract A process for recovering petroleum from a subterranean reservoir by flooding with a surfactant wherein the adsorption of surfactant by the reservoir rock is inhibited by treating the reservoir with a water-soluble fluorine containing compound such as hydrofluoric acid or sodium fluoride prior to injecting the surfactant. Preferably, treatment is accomplished by injecting an aqueous solution of hydrofluoric acid or sodium fluoride into the reservoir in an amount sufficient to satisfy substantially all of the adsorption capacity of the reservoir matrix followed by injection of an aqueous solution of the surfactant. The hydrofluoric acid or sodium fluoride and the surfactant solution can be subsequently displaced through the formation by any convenient aqueous drive fluid including water.
Inventors
- 👤 D Feuerbacher
- 👤 M Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:46
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/845; E; E21; E21B; E21B43/00; E21B43/16; E21B43/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
26 words
The method of claim 1 wherein from about 100 to about 1,000 pounds of sodium fluoride is injected per acre foot of formation to be swept.
Claim 2
Dependent Claim
75 words
In a method of recovering oil from a subterranean petroleum containing formation wherein an aqueous flooding medium containing a surfactant adsorbable by the formation rock is injected through injection means and fluids are recovered from production means, the improvement which comprises injecting a water-soluble fluorine containing compund in the form of an aqueous solution having a concentration of from about 0.5 to about 1.5 normal into said formation prior to the injection of said surfactant.
Claim 3
Dependent Claim
76 words
In a method of recovering oil from a subterranean petroleum containing formation wherein an aqueous flooding medium containing a surfactant adsorbable by the formation rock is injected through injection means and fluids are recovered from production means, the improvement which comprises injecting a water soluble fluorine containing compound in the form of an aqueous solution of from about 0.5 to about 5 percent by weight hydrofluoric acid into said formation prior to injection of said surfactant.
Claim 4
Dependent Claim
22 words
The method of claim 4 wherein from about 0.005 to about 0.10 pore volumes of hydrofluoric acid is injected into said formation.
Claim 5
Dependent Claim
19 words
The method of claim 4 wherein the aqueous solution of water soluble flourine containing compound also contains sodium chloride.
Claim 6
Dependent Claim
59 words
In a method of recovering oil from a subterranean petroleum containing formation wherein a surfactant adsorbable by the formation rock is injected through injection means and fluids are recovered from production means, the improvement which comprises injecting a water soluble fluorine containing compound as an aqueous solution of from about 1 to about 10 percent by weight sodium fluoride.
Claim 7
Dependent Claim
24 words
The method of claim 7 wherein from about 0.005 to about 0.10 pore volumes of aqueous sodium fluoride solution are injected into said formation.
Claim 8
Dependent Claim
18 words
The method of claim 7 wherein the surfactant is in an aqueous solution which also contains sodium chloride.
Claim 9
Dependent Claim
70 words
In a method of recovering oil from a subterranean petroleum containing formation wherein an aqueous flooding medium containing a surfactant adsorbable by the formation rock is injected through injection means and fluids are recovered from production means, the improvement which comprises injecting from about 50 to about 500 pounds of hydrofluoric acid per acre foot of formation to be swept into said formation prior to the injection of said surfactant.
Claim 10
Dependent Claim
74 words
In a method of recovering oil from a subterranean, petroleum containing formation wherein an aqueous flooding medium containing a surfactant adsorbable by the formation is injected into the formation through injection means and fluids are recovered from production means, the improvement which comprises injecting from about 0.005 to about 0.10 pore volumes of an aqueous solution of a water soluble salt of hydrofluoric acid into the formation prior to the injection of said surfactant.
Claim 11
Dependent Claim
28 words
A method as recited in claim 11 wherein the concentration of water soluble salt of hydrofluoric acid is from about 1.0 percent to about 10.0 percent by weight.
Claim 12
Dependent Claim
18 words
A method as recited in claim 11 wherein the water soluble salt of hydrofluoric acid is sodium fluoride.
Claim 13
Dependent Claim
29 words
The method of claim 11 wherein the surfactant is in the form of an aqueous solution which further contains the water soluble fluorine containing compound used in the preflush.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |