Patent US3805170A successfully refreshed from Google Patents.
US3994342A
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Microemulsion flooding process
Assignee: ExxonMobil Upstream Research Co
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Filing: 1975-07-03
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Granted: 1976-11-30
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Expires: 1995-07-03
Abstract
Abstract Crude oil remaining in a subterranean formation is recovered through the injection of a microemulsion comprising an oil, i.e. a refined or crude oil, an aqueous medium and as a surfactant, a C 8-16 orthoxylene sulfonate. The aqueous medium is preferably a brine having a salt concentration of up to about 2 1/2% by weight, although increased brine tolerance can be achieved by inclusion of a cosurfactant within the microemulsion. When utilized in the secondary or tertiary recovery of crude oil, the microemulsion is preferably followed by thickened water and thereafter unthickened water injected into and through the subterranean formation.
Inventors
- 👤 Robert N. Healy
- 👤 Walter W. Gale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:07
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/584
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
86 words
In a secondary or tertiary method of recovering crude oil from a subterranean formation wherein a microemulsion is injected into the formation through at least one injection means to displace crude oil in the formation toward at least one production means, the improvement wherein said microemulsion comprises an oil, an aqueous medium, and in am amount sufficient to produce a single-phase microemulsion a surfactant comprising a C 8-16 -orthoxylene sulfonate, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dyne/cm with the crude oil.
Claim 2
Dependent Claim
86 words
In a secondary or tertiary method of recovering crude oil from a subterranean formation wherein a microemulsion is injected into the formation through at least one injection means to displace crude oil in the formation toward at least one production means, the improvement wherein said microemulsion comprises an oil, an aqueous medium, and in am amount sufficient to produce a single-phase microemulsion a surfactant comprising a C 8-16 -orthoxylene sulfonate, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dyne/cm with the crude oil.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said microemulsion is miscible with said crude oil.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein said microemulsion exhibits an interfacial tension of from 0.0 to 0.04 dyne/cm with the crude oil.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said surfactant is a C 12 -orthoxylene sulfonate.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein said surfactant is in the form of a monoethanolamine salt of a C.sub. 8-16 -orthoxylene sulfonic acid.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein said aqueous medium is a brine with a salt concentration of up to 21/2% by weight.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein said brine has physical and chemical properties which are substantially the same as those of the brine in the subterranean formation.
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein said microemulsion further contains a cosurfactant.
Claim 10
Dependent Claim
31 words
The method of claim 8 wherein said cosurfactant is selected from alcohols, ethoxylated alcohols, sulfated ethoxylated alcohols, sufonated ethoxylated alcohols, ethoxylated phenols, sulfated ethoxylated phenols, sulfonated ethoxylated phenols and synthetic sulfonates.
Claim 11
Dependent Claim
14 words
The method of claim 8 wherein said cosurfactant is a C 1-7 orthoxylene sulfonate.
Claim 12
Dependent Claim
27 words
The method of claim 8 wherein said cosurfactant is present in an amount of from about 0.01 to about 20% based on the volume of the microemulsion.
Claim 13
Dependent Claim
26 words
The method of claim 1 wherein said surfactant is present in an amount of about 0.1 to about 15% based on the volume of the microemulsion.
Claim 14
Dependent Claim
28 words
The method of claim 1 wherein said oil has physical and chemical properties which are substantially the same as those of the crude oil in the subterranean formation.
Claim 15
Dependent Claim
22 words
The method of claim 1 wherein the injection of said microemulsion is preceded by primary depletion and waterflooding of said subterranean formation.
Claim 16
Dependent Claim
17 words
The method of claim 14 wherein said microemulsion is injected as a 0.03 to 0.6 PV slug.
Claim 17
Dependent Claim
33 words
The method of claim 15 wherein thickened water and then unthickened water are injected into said subterranean formation subsequent to said slug of microemulsion to drive said slug of microemulsion through said formation.
Claim 18
Independent Claim
144 words
A method of recovering residual oil from a subterranean formation which has been subjected to primary depletion and waterflooding which comprises: a. injecting into the flooded-out formation through at least one injection means in fluid communication with at least one production means a slug of a single-phase microemulsion comprising an oil, an aqueous medium and, in an amount sufficient to produce said single-phase microemulsion, a surfactant comprising a C 8-16 -orthoxylene sulfonate, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dynes/cm with the crude oil, said microemulsion being capable of displacing residual crude oil in said formation toward said production means; b. thereafter injecting thickened water to drive said slug of microemulsion through said formation toward said production means; c. injecting unthickened water subsequent to the injection of said thickened water; and d. recovering residual crude oil through said production means.
Claim 19
Independent Claim
144 words
A method of recovering residual oil from a subterranean formation which has been subjected to primary depletion and waterflooding which comprises: a. injecting into the flooded-out formation through at least one injection means in fluid communication with at least one production means a slug of a single-phase microemulsion comprising an oil, an aqueous medium and, in an amount sufficient to produce said single-phase microemulsion, a surfactant comprising a C 8-16 -orthoxylene sulfonate, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dynes/cm with the crude oil, said microemulsion being capable of displacing residual crude oil in said formation toward said production means; b. thereafter injecting thickened water to drive said slug of microemulsion through said formation toward said production means; c. injecting unthickened water subsequent to the injection of said thickened water; and d. recovering residual crude oil through said production means.
Claim 20
Dependent Claim
14 words
The method of claim 17 wherein said microemulsion is miscible with said crude oil.
Claim 21
Dependent Claim
22 words
The method of claim 17 wherein said microemulsion exhibits an interfacial tension of from 0.0 to 0.04 dynes/cm with the crude oil.
Claim 22
Dependent Claim
14 words
The method of claim 17 wherein said surfactant is a C 12 -orthoxylene sulfonate.
Claim 23
Dependent Claim
23 words
The method of claim 17 wherein said surfactant is in the form of a monoethanolamine salt of a C 8-16 -orthoxylene sulfonic acid.
Claim 24
Dependent Claim
22 words
The method of claim 17 wherein said aqueous medium is a brine with a salt concentration of up to 21/2% by weight.
Claim 25
Dependent Claim
12 words
The method of claim 17 wherein said microemulsion further contains a cosurfactant.
Claim 26
Dependent Claim
31 words
The method of claim 23 wherein said cosurfactant is selected from alcohols, ethoxylated alcohols, sulfated ethoxylated alcohols, sulfonated ethoxylated alcohols, ethoxylated phenols, sulfated ethoxylated phenols, sulfonated ethoxylated phenols and synthetic sulfonates.
Claim 27
Dependent Claim
14 words
The method of claim 23 wherein said cosurfactant is a C 1-7 orthoxylene sulfonate.
Claim 28
Dependent Claim
26 words
The method of claim 23 whereinsaid cosurfactant is present in an amount of from about 0.01 to about 20% based on the volume of the microemulsion.
Claim 29
Dependent Claim
26 words
The method of claim 17 wherein said surfactant is present in an amount of about 0.1 to about 15% based on the volume of the microemulsion.
Claim 30
Dependent Claim
17 words
The method of claim 17 wherein said microemulsion is injected as a 0.03 to 0.6 PV slug.
Claim 31
Dependent Claim
93 words
In a secondary or tertiary method of recovering crude oil from a subterranean formation wherein a microemulsion is injected into the formation through at least one injection means to displace crude oil in the formation toward at least one production means, the improvement wherein said microemulsion comprises an oil, an aqueous medium, in an amount sufficient to produce a single-phase microemulsion a surfactant comprising a C 8-16 -orthoxylene sulfonate, and a co-surfactant comprising a sulfonated ethoxylated phenol, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dyne/cm with the crude oil.
Claim 32
Dependent Claim
93 words
In a secondary or tertiary method of recovering crude oil from a subterranean formation wherein a microemulsion is injected into the formation through at least one injection means to displace crude oil in the formation toward at least one production means, the improvement wherein said microemulsion comprises an oil, an aqueous medium, in an amount sufficient to produce a single-phase microemulsion a surfactant comprising a C 8-16 -orthoxylene sulfonate, and a co-surfactant comprising a sulfonated ethoxylated phenol, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dyne/cm with the crude oil.
Claim 33
Independent Claim
155 words
A method of recovering residual oil from a subterranean formation which has been subjected to primary depletion and waterflooding which comprises: a. injecting into the flooded-out formation through at least one injection means in fluid communication with at least one production means a slug of a single-phase microemulsion comprising i. an oil, ii. an aqueous medium, iii. in an amount sufficient to produce said single-phase microemulsion, a surfactant comprising a C 8-16 -orthoxylene sulfonate, and iv. a co-surfactant comprising a sulfonated ethoxylated phenol, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dynes/cm with the crude oil, said microemulsion being capable of displacing residual crude oil in said formation toward said production means; b. thereafter injecting thickened water to drive said slug of microemulsion through said formation toward said production means; c. injecting unthickened water subsequent to the injection of said thickened water; and d. recovering residual crude oil through said production means.
Claim 34
Independent Claim
155 words
A method of recovering residual oil from a subterranean formation which has been subjected to primary depletion and waterflooding which comprises: a. injecting into the flooded-out formation through at least one injection means in fluid communication with at least one production means a slug of a single-phase microemulsion comprising i. an oil, ii. an aqueous medium, iii. in an amount sufficient to produce said single-phase microemulsion, a surfactant comprising a C 8-16 -orthoxylene sulfonate, and iv. a co-surfactant comprising a sulfonated ethoxylated phenol, said microemulsion exhibiting an interfacial tension of from 0.0 to 0.1 dynes/cm with the crude oil, said microemulsion being capable of displacing residual crude oil in said formation toward said production means; b. thereafter injecting thickened water to drive said slug of microemulsion through said formation toward said production means; c. injecting unthickened water subsequent to the injection of said thickened water; and d. recovering residual crude oil through said production means.
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) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |