Patent US2472837A successfully refreshed from Google Patents.
Patent US4776398A successfully refreshed from Google Patents.
US4776398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oil reservoir permeability control
Assignee: Mobil Oil AS
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Filing: 1987-04-30
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Granted: 1988-10-11
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Expires: 2007-04-30
Abstract
Abstract The permeability of a subterranean oil-bearing formation is controlled by the injection of an aqueous solution of a cross-linked block copolymer containing polar and non-polar segments, with the polar segments generally making up at least 50 percent, usually 60 to 99 percent, of the copolymer. The polar segments are derived from an alkylene oxide and the non-polar segments from styrene or an alkyl styrene either by itself or with a diene. The copolymers are cross-linked with an amino resin or a combination of a phenolic and a water-dispersible aldehyde component. The resulting copolymer gels are stable at low pH conditions, such as those of CO 2 flood conditions.
Inventors
- 👤 A. S. Chu
- 👤 Harold S. Chung
- 👤 Dennis H. Hoskin
- 👤 Thomas O. Mitchell
- 👤 Paul Shu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:11
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/86; C09K8/88; C09K8/887; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/5083; C09K8/512; C09K8/514; C09K8/58; C09K8/588; C09K8/90; C09K8/905; Y; Y10; Y10S; Y10S507/00; Y10S507/903; Y10S507/935
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
102 words
A method for controlling the permeability of a subterranean formation, which comprises injecting into the formation an aqueous solution of a cross-linked block copolymer having at least one polar and at least one non-polar segment, the polar segment being derived from a polymerized alkylene oxide and the non-polar segment from styrene or an alkylstyrene, the polar segments constituting at least 30 weight percent of the copolymer, the block copolymer being cross-linked with a cross-linking agent which is an amino resin or a combination of a phenolic component and a water-dispersible aldehyde component to selectively block the high permeability regions of the formation.
Claim 2
Independent Claim
102 words
A method for controlling the permeability of a subterranean formation, which comprises injecting into the formation an aqueous solution of a cross-linked block copolymer having at least one polar and at least one non-polar segment, the polar segment being derived from a polymerized alkylene oxide and the non-polar segment from styrene or an alkylstyrene, the polar segments constituting at least 30 weight percent of the copolymer, the block copolymer being cross-linked with a cross-linking agent which is an amino resin or a combination of a phenolic component and a water-dispersible aldehyde component to selectively block the high permeability regions of the formation.
Claim 3
Dependent Claim
21 words
A method according to claim 1 in which the polar segment constitutes at least about 50 weight percent of the copolymer.
Claim 4
Dependent Claim
23 words
A method according to claim 2 in which the polar segment constitutes from about 60 to about 99 weight percent of the copolymer.
Claim 5
Dependent Claim
23 words
A method according to claim 3 in which the polar segment constitutes from about 60 to about 80 weight percent of the copolymer.
Claim 6
Dependent Claim
17 words
A method according to claim 4 in which the non-polar segment comprises copolymerized styrene and diene units.
Claim 7
Dependent Claim
15 words
A method according to claim 5 in which the non-polar segment comprises polymerized alkylstyrene units.
Claim 8
Dependent Claim
15 words
A method according to claim 5 in which the non-polar segment comprises polymerized styrene units.
Claim 9
Dependent Claim
18 words
A method according to claim 7 in which the copolymer has solubilizing functional groups on the non-polar segment.
Claim 10
Dependent Claim
18 words
A method according to claim 6 in which the copolymer has solubilizing functional groups on the non-polar segment.
Claim 11
Dependent Claim
15 words
A method according to claim 8 in which the solubilizing functional groups are sulfonate groups.
Claim 12
Dependent Claim
15 words
A method according to claim 9 in which the solubilizing functional groups are sulfonate groups.
Claim 13
Dependent Claim
21 words
A method according to claim 11 in which the copolymer comprises at least 1000 alkylene oxide units in the polar block.
Claim 14
Dependent Claim
21 words
A method according to claim 10 in which the copolymer comprises at least 1000 alkylene oxide units in the polar block.
Claim 15
Dependent Claim
19 words
A method according to claim 13 in which the copolymer has a molecular weight of from 50,000 to 300,000.
Claim 16
Dependent Claim
19 words
A method according to claim 12 in which the copolymer has a molecular weight of from 50,000 to 300,000.
Claim 17
Dependent Claim
20 words
A method according to claim 15 in which the solution contains about 1,000 to about 20,000 ppm of the copolymer.
Claim 18
Dependent Claim
20 words
A method according to claim 14 in which the solution contains about 1,000 to about 20,000 ppm of the copolymer.
Claim 19
Dependent Claim
20 words
A method according to claim 17 in which the solution contains about 2,000 to about 5,000 ppm of the copolymer.
Claim 20
Dependent Claim
20 words
A method according to claim 16 in which the solution contains about 2,000 to about 5,000 ppm of the copolymer.
Claim 21
Dependent Claim
20 words
A method according to claim 19 in which the amino resin is produced by reacting formaldehyde with urea or melamine.
Claim 22
Dependent Claim
20 words
A method according to claim 18 in which the amino resin is produced by reacting formaldehyde with urea or melamine.
Claim 23
Dependent Claim
14 words
A method according to claim 19 wherein the cross-linking agent is phenol/formaldehyde or resorcinol/formaldehyde.
Claim 24
Dependent Claim
155 words
In a method of recovering oil from an oil-bearing subterranean formation penetrated by an injection well and a production well, in which an aqueous fluid is injected into the formation through the injection well to displace oil to the production well, the improvement comprising employing, in at least the initial portion of the aqueous fluid injected into the formation, a water soluble block copolymer having at least one polar and at least one non-polar segment, the polar segment being derived from a polymerized alkylene oxide, and the non-polar segment from styrene or an alkyl styrene, the polar segments constituting at least 30 weight percent of the copolymer, the copolymer being cross-linked with a cross-linking agent which is an amino resin or a combination of a phenolic component and a water-dispersible aldehyde component, the copolymer being present in the fluid in an amount sufficient to provide improved efficiency in displacing the oil to the production well.
Claim 25
Dependent Claim
155 words
In a method of recovering oil from an oil-bearing subterranean formation penetrated by an injection well and a production well, in which an aqueous fluid is injected into the formation through the injection well to displace oil to the production well, the improvement comprising employing, in at least the initial portion of the aqueous fluid injected into the formation, a water soluble block copolymer having at least one polar and at least one non-polar segment, the polar segment being derived from a polymerized alkylene oxide, and the non-polar segment from styrene or an alkyl styrene, the polar segments constituting at least 30 weight percent of the copolymer, the copolymer being cross-linked with a cross-linking agent which is an amino resin or a combination of a phenolic component and a water-dispersible aldehyde component, the copolymer being present in the fluid in an amount sufficient to provide improved efficiency in displacing the oil to the production well.
Claim 26
Dependent Claim
32 words
A method according to claim 23 in which the amount of the copolymer is sufficient to provide a mobility ratio of at least 1 for the reservoir oil to the aqueous fluid.
Claim 27
Dependent Claim
18 words
A method according to claim 24 in which the copolymer has a molecular weight of 50,000 to 300,000.
Claim 28
Dependent Claim
20 words
A method according to claim 25 in which the copolymer comprises 60 to 99 weight percent of the polar segment.
Claim 29
Dependent Claim
20 words
A method according to claim 26 in which the copolymer comprises 60 to 80 weight percent of the polar segment.
Claim 30
Dependent Claim
19 words
A method according to claim 27 wherein the amino resin is produced by reacting formaldehyde with urea or melamine.
Claim 31
Dependent Claim
14 words
A method according to claim 27 wherein the cross-linking agent is phenol/formaldehyde or resorcinol/formaldehyde.
Claim 32
Dependent Claim
160 words
In a method of recovering oil from an oil-bearing subterranean formation penetrated by an injection well and a production well, in which an oil-miscible or oil-immiscible displacing fluid is injected into the formation through the injection well to displace oil to the production well, the improvement comprising injecting into the formation, prior to the injection of the displacing fluid, an aqueous fluid containing a water soluble block copolymer having at least one polar and at least one non-polar segment, the polar segment being derived from a polymerized alkylene oxide, and the non-polar segment from styrene or an alkyl styrene, the polar segments constituting at least 30 weight percent of the copolymer, the copolymer being cross-linked with a cross-linking agent which is an amino resin or a combination of a phenolic component and a water-dispersible aldehyde component, the copolymer being present in the aqueous fluid in an amount sufficient to provide improved efficiency in displacing the oil to the production well.
Claim 33
Dependent Claim
160 words
In a method of recovering oil from an oil-bearing subterranean formation penetrated by an injection well and a production well, in which an oil-miscible or oil-immiscible displacing fluid is injected into the formation through the injection well to displace oil to the production well, the improvement comprising injecting into the formation, prior to the injection of the displacing fluid, an aqueous fluid containing a water soluble block copolymer having at least one polar and at least one non-polar segment, the polar segment being derived from a polymerized alkylene oxide, and the non-polar segment from styrene or an alkyl styrene, the polar segments constituting at least 30 weight percent of the copolymer, the copolymer being cross-linked with a cross-linking agent which is an amino resin or a combination of a phenolic component and a water-dispersible aldehyde component, the copolymer being present in the aqueous fluid in an amount sufficient to provide improved efficiency in displacing the oil to the production well.
Claim 34
Dependent Claim
12 words
A method of claim 30 wherein the fluid is an oil-immiscible fluid.
Claim 35
Dependent Claim
11 words
A method of claim 31 wherein the fluid is carbon dioxide.
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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) | 1991-10-11 | 1992-04-11 | 1992-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-11 | 1996-04-11 | 1996-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-11 | 2000-04-11 | 2000-10-11 | $7700.00 | Window Closed / Lapsed |