US3722590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of mobility control in miscible displacement process
Assignee: BP America Production Co
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Filing: 1971-06-01
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Granted: 1973-03-27
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Expires: 1991-06-01
Abstract
Abstract In displacement by water of a solvent substantially miscible with both water and petroleum through a petroleum-containing reservoir, the mobility of the drive agent is controlled by generating a weak, mobile foam at or near the trailing edge of the solvent slug. Foams found to be suitable for this purpose, and which do not result in plugging the reservoir, are characterized by the fact that they have a maximum viscosity of not more than about 1,000 cps and when confined in a column over a 20-minute period decrease in volume to not more than one-third of the foam present at the beginning of said period.
Inventors
- 👤 W Askew
- 👤 H Froning
- 👤 S Raza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:42
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/20; C; C09; C09K; C09K8/00; C09K8/58; C09K8/594
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
124 words
In a method for recovering oil from an underground formation penetrated by an injection well and a producing well, the improvement which comprises the steps of: injecting into said formation via said injection well a liquid solvent for said oil, said solvent being present in an amount sufficient to form a bank thereof, forming substantially at the trailing edge of said solvent as a mobility buffer a weak, mobile foam which when confined in a column over a 20-minute period decreases in volume to not more than about one-third of its original volume at the beginning of said period, thereafter displacing said oil, solvent bank and said foam bank through said formation towards said producing well, and recovering displaced oil from said producing well.
Claim 2
Dependent Claim
14 words
The method of claim 1 wherein said solvent is a salt containing micellar solution.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein said foam is generated by injecting a gas followed by water.
Claim 4
Dependent Claim
23 words
The method of claim 4 wherein said foam bank is characterized by its deterioration and regeneration as it is displaced through said formation.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said solvent is capable of producing an interfacial tension between it and the oil of less than 0.1 dyne per cm.
Claim 6
Dependent Claim
25 words
The method of claim 3 wherein said micellar solution contains a petroleum sulfonate surfactant having a molecular weight ranging from about 400 to about 470.
Claim 7
Dependent Claim
54 words
The method of claim 1 wherein an aqueous slug of surfactant is injected behind and is in close proximity with said solvent and forms said foam bank by agitating said surfactant slug with a fluid, said foam bank continuously forming at the trailing edge of said solvent slug while previously formed foam is collapsing.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein the liquid solvent employed is miscibly displaced by water.
Claim 9
Dependent Claim
18 words
The method of claim 1 wherein said foam bank is brought into contact with an alcoholic brine solution.
Claim 10
Dependent Claim
17 words
The method of claim 1 wherein said solvent is a micellar solution containing a water soluble alcohol.
Claim 11
Dependent Claim
33 words
The method of claim 1 wherein said foam bank is formed from an aqueous brine solution of surfactant in which the surfactant and brine solution are employed in a ratio of about 1:3.
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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |