US4498539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective plugging of highly permeable subterranean strata by in situ _gelation of polymer solutions
Assignee: Phillips Petroleum Co
•
Filing: 1983-11-16
•
Granted: 1985-02-12
•
Expires: 2003-11-16
Abstract
Abstract A water permeability correction process, and composition therefor, to improve the sweep efficiency of waterflooding which involves the sequential injection of (1) an optional aqueous preflush slug to adjust connate water salinity, (2) an aqueous thickened slug comprising a sequestered polyvalent metal cation such as aluminum citrate, a gelable polymeric viscosifier such as polyacrylamide, and a hydrolyzable-pH-adjusting ester effective for delayed decreasing of the pH of the polymer slug which triggers in situ gelation to preferentially decrease water permeability in highly permeable thief zones, and, preferably, (3) an aqueous drive fluid.
Inventors
- 👤 Donald D. Bruning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:03
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/512
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
69 words
A method for treating an underground formation which comprises injecting effective permeability control proportions of an in situ gelable composition comprising effective ratios of: (a) water, (b) at least one polymer capable of gelling with a crosslinking agent within a gelation pH range, (c) at least one crosslinking agent comprised of sequestered polyvalent metal cations, (d) at least one sequestering anion, and (e) at least one hydrolyzable organic ester.
Claim 2
Independent Claim
69 words
A method for treating an underground formation which comprises injecting effective permeability control proportions of an in situ gelable composition comprising effective ratios of: (a) water, (b) at least one polymer capable of gelling with a crosslinking agent within a gelation pH range, (c) at least one crosslinking agent comprised of sequestered polyvalent metal cations, (d) at least one sequestering anion, and (e) at least one hydrolyzable organic ester.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said polymer is present in said in situ gelable composition in an amount of about 500 to 10,000 ppm.
Claim 4
Dependent Claim
24 words
A method according to claim 2 wherein said polymer comprises polyacrylamide, said polyvalent cation compries Al 3+ , and said chelating/sequestering anion comprises citrate.
Claim 5
Dependent Claim
43 words
The method of claim 2 employing in said in situ gelable composition a range of about 10:1 to 1:10 ratio of polyvalent metal cation to cross-linkable groups of the polymer; and a molar ratio of about 1:1 to 6:1 polyvalent metal cation:sequestering agent.
Claim 6
Dependent Claim
30 words
The method of claim 1 wherein said polymer is selected from the groups consisting of biopolysaccharides, cellulose ethers, acrylamide-based polymer, partially hydrolyzed polyacrylonitriles, polystyrene sulfonates, lignosulfonates, methylolated polyacrylamides, and mixtures.
Claim 7
Dependent Claim
68 words
The method of claim 5 wherein said polyvalent metal cation is selected from the group consisting of Fe 2+ , Fe 3+ , Al 3+ , Ti 4+ , Zn 2+ , Sn 4+ , Ca 2+ , Mg 2+ , Cr 3+ , and mixtures; and said chelating/sequestering agent is selected from the group consisting of acetate, nitrilotriacetate, tartrate, citrate, tripolyphosphate, metaphosphate, gluconate, phosphate, and mixtures thereof.
Claim 8
Dependent Claim
28 words
The process of claim 6 wherein said hydrolyzable ester is selected from the formates, acetates, propionates, butyrates, and valerates of monohydric alcohols containing 1 to 5 carbon atoms.
Claim 9
Dependent Claim
36 words
The process of claim 7 wherein said ester is selected from the group consisting of methyl acetate, ethyl propionate, propyl formate, isopropyl acetate, n-butyl acetate, isopropyl propionate, amyl formate, ethyl butyrate, methyl propionate, and mixtures thereof.
Claim 10
Dependent Claim
52 words
The process of claim 8 employing in said aqueous gelable composition about: 500 ppm to 10,000 ppm of said polymer; about 10:1 to 1:10 ratio of said polyvalent metal cation:cross-linkable groups of the polymer; and about 0.1 to 1 weight percent of said ester based on the total weight of said composition.
Claim 11
Dependent Claim
16 words
The process of claim 1 preceded by an aqueous preflush slug to adjust connate water salinity.
Claim 12
Dependent Claim
104 words
A process of controlling sweep efficiency in a subterranean formation which comprises the sequential injection of effective quantities of: (1) an aqueous preflush slug to adjust connate water salinity, (2) an in situ gelable aqueous thickened slug comprising a sequestered polyvalent metal cation, a gelable polymeric viscosifier, and a hydrolyzable pH-reducing organic ester, and (3) an aqueous drive fluid; wherein said ester is a hydrolyzable-pH-adjusting ester effective to decrease in situ of the pH of said thickened slug so as to trigger delayed in situ gelation of the thickened slug thus effecting preferential decrease in water permeability of the otherwise highly permeable thief zones.
Claim 13
Dependent Claim
104 words
A process of controlling sweep efficiency in a subterranean formation which comprises the sequential injection of effective quantities of: (1) an aqueous preflush slug to adjust connate water salinity, (2) an in situ gelable aqueous thickened slug comprising a sequestered polyvalent metal cation, a gelable polymeric viscosifier, and a hydrolyzable pH-reducing organic ester, and (3) an aqueous drive fluid; wherein said ester is a hydrolyzable-pH-adjusting ester effective to decrease in situ of the pH of said thickened slug so as to trigger delayed in situ gelation of the thickened slug thus effecting preferential decrease in water permeability of the otherwise highly permeable thief zones.
Claim 14
Dependent Claim
14 words
The process of claim 11 wherein said aqueous preflush comprises a sodium chloride brine.
Claim 15
Dependent Claim
107 words
The process of claim 12 wherein said in situ gelable slug comprising effective ratios of: (a) water, (b) a polymer capable of gelling with a crosslinking agent at a pH in the gelation range of 3 to 7, (c) a crosslinking agent comprised of sequestered polyvalent metal cations, selected from the group consisting of Fe 2+ , Fe 3+ , Al 3+ , Ti 4+ , Zn 2+ , Sn 4+ , Ca 2+ , Mg 2+ , and Cr 3+ , (d) chelating anions selected from the group consisting of acetate, nitrilotriacetate, tartrate, citrate, tripolyphosphate, metaphosphate, gluconate, phosphate, and mixtures thereof, and (e) said hydrolyzable ester.
Claim 16
Dependent Claim
23 words
The method of claim 13 wherein the polymer is present in said gelable composition in an amount of about 500 to 10,000 ppm.
Claim 17
Dependent Claim
26 words
A method according to claim 14 wherein the polymer comprises partially hydrolyzed polyacrylamide, said multivalent cation comprises Al 3+ , and said chelating anion comprises citrate.
Claim 18
Dependent Claim
50 words
The method of claim 14 wherein said multivalent cation is present in said aqueous gelable solution in a ratio of about 10:1 to 1:10 polyvalent metal cation:cross-linkable groups of the polymer; and said chelating anion is present in a molar ratio of about 1:1 to 6:1 polyvalent metal cation:sequestering anion.
Claim 19
Dependent Claim
30 words
The process of claim 16 wherein said polymer is selected from the groups consisting of biopolysaccharides, cellulose ethers, acrylamide-based polymers, partially hydrolyzed polyacrylonitriles, polystyrene sulfonates, lignosulfonates, methylolated polyacrylamides, and mixtures.
Claim 20
Dependent Claim
28 words
The process of claim 17 wherein said hydrolyzable ester is selected from the formates, acetates, propionates, butyrates, and valerates of monohydric alcohols containing 1 to 5 carbon atoms.
Claim 21
Dependent Claim
36 words
The process of claim 18 wherein said ester is selected from the group consisting of methyl acetate, ethyl propionate, propyl formate, isopropyl acetate, n-butyl acetate, isopropyl propionate, amyl formate, ethyl butyrate, methyl propionate, and mixtures thereof.
Claim 22
Dependent Claim
52 words
The process of claim 19 employing in said aqueous gelable composition about: 500 ppm to 10,000 ppm of said polymer; about 10:1 to 1:10 ratio of said polyvalent metal cation:cross-linkable groups of the polymer; and about 0.1 to 1 weight percent of said ester based on the total weight of said composition.
Claim 23
Dependent Claim
24 words
A process according to claim 20 wherein said polymer comprises polyacrylamide, the polyvalent cation is Al 3+ , and the chelating/sequestering anion is citrate.
Claim 24
Dependent Claim
100 words
A gelable composition comprising effective gelation ratios of: (a) water, (b) a polymer capable of gelling with a crosslinking agent at a pH in the range of 3 to 7, (c) a crosslinking agent comprised of sequestered polyvalent metal cations, selected from the group consisting of Fe 2+ , Fe 3+ , Al 3+ , Ti 4+ , Zn 2+ , Sn 4+ , Ca 2+ , Mg 2+ , and Cr 3+ , (d) chelating/sequestering anions selected from the group consisting of acetate, nitrilotriacetate, tartrate, citrate, tripolyphosphate, metaphosphate, gluconate, phosphate, and mixtures thereof, and (e) a hydrolyzable organic ester.
Claim 25
Dependent Claim
100 words
A gelable composition comprising effective gelation ratios of: (a) water, (b) a polymer capable of gelling with a crosslinking agent at a pH in the range of 3 to 7, (c) a crosslinking agent comprised of sequestered polyvalent metal cations, selected from the group consisting of Fe 2+ , Fe 3+ , Al 3+ , Ti 4+ , Zn 2+ , Sn 4+ , Ca 2+ , Mg 2+ , and Cr 3+ , (d) chelating/sequestering anions selected from the group consisting of acetate, nitrilotriacetate, tartrate, citrate, tripolyphosphate, metaphosphate, gluconate, phosphate, and mixtures thereof, and (e) a hydrolyzable organic ester.
Claim 26
Dependent Claim
24 words
The gelable composition of claim 22 wherein the polymer is present in said gelable composition in an amount of about 500 to 10,000 ppm.
Claim 27
Dependent Claim
52 words
The gelable composition of claim 23 wherein the multivalent cation is present in said aqueous gelable solution in a molar ratio of about 10:1 to 1:10 polyvalent metal cation:cross-linkable groups of the polymer; and said chelating anion is present in a molar ratio of about 1:1 to 6:1 polyvalent metal cation:sequestering anion.
Claim 28
Dependent Claim
31 words
The gelable composition of claim 24 wherein said polymer is selected from the groups consisting of biopolysaccharides, cellulose ethers, acrylamide-based polymers, partially hydrolyzed polyacrylonitriles, polystyrene sulfonates, lignosulfonates, methylolated polyacrylamides, and mixtures.
Claim 29
Dependent Claim
32 words
The gelable composition of claim 25 wherein said hydrolyzable ester is selected from the group consisting of formates, acetates, propionates, butyrates, and valerates of monohydric alcohols containing 1 to 5 carbon atoms.
Claim 30
Dependent Claim
37 words
The gelable composition of claim 26 wherein said ester is selected from the group consisting of methyl acetate, ethyl propionate, propyl formate, isopropyl acetate, n-butyl acetate, isopropyl propionate, amyl formate, ethyl butyrate, methyl propionate, and mixtures thereof.
Claim 31
Dependent Claim
48 words
The gelable composition of claim 26 employing about: 500 ppm to 10,000 ppm of said polymer; about 10:1 to 1:10 ratio of said polyvalent metal cation:cross-linkable groups of the polymer; and about 0.1 to 1 weight percent of said ester based on the total weight of said composition.
References Cited (Backward Citations)
US3386509A
Cited
US3741894A
Cited
US3699042A
Cited
US3795276A
Cited
US3762476A
Cited
US3727689A
Cited
US3749172A
Cited
US3815681A
Cited
US3782467A
Cited
US3753971A
Cited
US3785437A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |