US4643256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steam-foaming surfactant mixtures which are tolerant of divalent ions
Assignee: Shell USA Inc
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Filing: 1985-03-18
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Granted: 1987-02-17
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Expires: 2005-03-18
Abstract
Abstract In a steam-foam-displacement of oil within a reservoir formation having a significant ion-exchange capacity for releasing multivalent cations, the rate of the steam foam propagation is increased by injecting a mixture of steam and a steam-foaming surfactant mixture comprising an independently effective steam-foaming sulfonate surfactant mixed with a lesser amount of an alkyl or alkylarylpolyalkoxyalkylene sulfonate cosurfactant.
Inventors
- 👤 Richard E. Dilgren
- 👤 Kenneth B. Owens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:25
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; C; C09; C09K; C09K8/00; C09K8/58; C09K8/592
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
70 words
In a process in which oil is displaced by injecting steam and steam-foaming surfactant into a subterranean reservoir having an ion-exchange capacity capable of reducing the rate of propagation of the surfactant through the reservoir due to a tendency for polyvalent cations from ion-exchange sites within the reservoir to be exchanged for monovalent cations dissolved in the injected fluids, an improvement for enhancing the rate of surfactant propagation which comprises:
Claim 2
Dependent Claim
70 words
In a process in which oil is displaced by injecting steam and steam-foaming surfactant into a subterranean reservoir having an ion-exchange capacity capable of reducing the rate of propagation of the surfactant through the reservoir due to a tendency for polyvalent cations from ion-exchange sites within the reservoir to be exchanged for monovalent cations dissolved in the injected fluids, an improvement for enhancing the rate of surfactant propagation which comprises:
Claim 3
Dependent Claim
94 words
injecting a reservoir-tailored steam-foaming surfactant mixture consisting essentially of (a) a predominant amount of a sulfonate surfactant which, by itself in the presence of the reservoir oil and in the absence of polyvalent cations, is capable of yielding a steam foam of significantly reduced mobility, and (b) a lesser amount of an alkylpolyalkoxyalkylene or an alkylarylpolyalkoxyalkylene sulfonate surfactant which is effective for causing the steam-foaming surfactant mixture to be capable of yielding a steam foam of significantly reduced mobility in the presence of the reservoir oil and the ion-exchangeable cations on the reservoir rocks.
Claim 4
Dependent Claim
94 words
injecting a reservoir-tailored steam-foaming surfactant mixture consisting essentially of (a) a predominant amount of a sulfonate surfactant which, by itself in the presence of the reservoir oil and in the absence of polyvalent cations, is capable of yielding a steam foam of significantly reduced mobility, and (b) a lesser amount of an alkylpolyalkoxyalkylene or an alkylarylpolyalkoxyalkylene sulfonate surfactant which is effective for causing the steam-foaming surfactant mixture to be capable of yielding a steam foam of significantly reduced mobility in the presence of the reservoir oil and the ion-exchangeable cations on the reservoir rocks.
Claim 5
Dependent Claim
16 words
The process of claim 1 in which said alkylene sulfonate surfactant is an alkylpolyalkoxyalkylene sulfonate surfactant.
Claim 6
Dependent Claim
22 words
The process of claim 2 in which the alkyl group of said alkylene sulfonate surfactant contains about 9 to 11 carbon atoms.
Claim 7
Dependent Claim
27 words
The process of claim 1 in which the independently effective sulfonate surfactant is an alpha-olefin sulfonate surfactant derived from olefins containing about 15 to 20 carbon atoms.
Claim 8
Dependent Claim
37 words
The process of claim 4 in which the alkylene group of said alkylene sulfonate surfactant contains about 2 to 3 carbon atoms and that surfactant contains an average of about 2 to 10 polyethoxy or polypropoxy groups.
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) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |