US5360065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scale inhibitor and process for using
Assignee: Marathon Oil Co
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Filing: 1993-06-29
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Granted: 1994-11-01
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Expires: 2013-06-29
Abstract
Abstract A copolymer of sodium vinyl sulfonate and polyalkylene glycol mono- or di-methacrylate and a process for inhibiting scale deposition, particularly inorganic sulfate such as barium sulfate. An aqueous fluid present in or produced from a subterranean formation is contacted with an aqueous solution having the copolymer dissolved therein. The aqueous fluid has an acidic pH and the copolymer has a molecular weight of from about 2,000 to about 30,000.
Inventors
- 👤 David O. Falk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:52
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C09; C09K; C09K8/00; C09K8/52; C09K8/528
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
70 words
A process for inhibiting scale including barium sulfate in aqueous fluid and being present in or produced from a subterranean formation, the process comprising: contacting said aqueous fluid with an amount of a copolymer of sodium vinyl sulfonate and polyalkylene glycol mono- or di-methacrylate which is effective to inhibit formation of said scale in said aqueous fluid, said copolymer having a molecular weight of from about 2,000 to about 30,000.
Claim 2
Dependent Claim
70 words
A process for inhibiting scale including barium sulfate in aqueous fluid and being present in or produced from a subterranean formation, the process comprising: contacting said aqueous fluid with an amount of a copolymer of sodium vinyl sulfonate and polyalkylene glycol mono- or di-methacrylate which is effective to inhibit formation of said scale in said aqueous fluid, said copolymer having a molecular weight of from about 2,000 to about 30,000.
Claim 3
Dependent Claim
60 words
The process of claim 1 further comprising: injecting an aqueous solution having said copolymer dissolved therein into said subterranean formation via a well bore in fluid communication with said subterranean formation, said copolymer being absorbed within a matrix of said subterranean formation, said step of contacting being performed as said copolymer is desorbed from said matrix into said aqueous fluid.
Claim 4
Dependent Claim
29 words
The process of claim 2 wherein said copolymer is dissolved into said aqueous solution in an amount of from about 0.4 to about 25 volume percent of the solution.
Claim 5
Dependent Claim
29 words
The process of claim 3 wherein said copolymer is dissolved into said aqueous solution in an amount of from about 2 to about 20 volume percent of the solution.
Claim 6
Dependent Claim
29 words
The process of claim 4 wherein said copolymer is dissolved into said aqueous solution in an amount of from about 5 to about 10 volume percent of the solution.
Claim 7
Dependent Claim
21 words
The process of claim 2 further comprising: determining the concentration of copolymer in said aqueous fluid produced from said subterranean formation.
Claim 8
Dependent Claim
45 words
The process of claim 6 wherein said concentration of copolymer in said aqueous fluid produced from said formation is determined to be below a predetermined value, the process further comprising: repeating said injection of said aqueous solution having copolymer dissolved therein into said subterranean formation.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein said predetermined value is 40 ppm.
Claim 10
Dependent Claim
12 words
The process of claim 7 wherein said predetermined value is 50 ppm.
Claim 11
Dependent Claim
12 words
The process of claim 7 wherein said predetermined value is 100 ppm.
Claim 12
Dependent Claim
29 words
The process of claim 2 further comprising: injecting a second aqueous solution into said subterranean formation via said well bore to displace said aqueous solution having copolymer dissolved therein.
Claim 13
Dependent Claim
39 words
The process of claim 1 wherein said well bore is a production well bore, said process further comprising: shutting in said well bore for a predetermined period of time subsequent to said step of injecting said second aqueous solution.
Claim 14
Dependent Claim
12 words
The process of claim 2 wherein said aqueous solution is a brine.
Claim 15
Dependent Claim
11 words
The process of claim 13 wherein said brine contains sulfate ions.
Claim 16
Dependent Claim
21 words
The process of claim 2 further comprising: removing deleterious by-products of sulfonation from said aqueous solution prior to said contacting step.
Claim 17
Dependent Claim
19 words
The process of claim 2 wherein said copolymer has a molecular weight of from about 5,000 to about 30,000.
Claim 18
Dependent Claim
19 words
The process of claim 2 wherein said copolymer has a molecular weight of from about 10,000 to about 25,000.
Claim 19
Dependent Claim
16 words
The process of claim 2 wherein said copolymer has a polydispersity of less than about 2.0.
Claim 20
Dependent Claim
14 words
The process of claim 1 wherein said aqueous fluid has carbon dioxide dissolved therein.
Claim 21
Dependent Claim
19 words
The process of claim 1 wherein said copolymer has a molecular weight of from about 5,000 to about 30,000.
Claim 22
Dependent Claim
19 words
The process of claim 1 wherein said copolymer has a molecular weight of from about 10,000 to about 25,000.
Claim 23
Dependent Claim
16 words
The process of claim 1 wherein said copolymer has a polydispersity of less than about 2.0.
Claim 24
Dependent Claim
49 words
The process of claim 1 wherein said step of contacting is performed by metering an aqueous solution having said copolymer dissolved therein through a small diameter tube positioned within a well bore in fluid communication with said subterranean formation and into said aqueous fluid present in said well bore.
Claim 25
Dependent Claim
31 words
The process of claim 1 wherein said process further comprises: injecting said copolymer into a well bore in fluid communication with said subterranean formation, said copolymer being encapsulated prior to injection.
Claim 26
Dependent Claim
16 words
The process of claim 1 wherein said polyalkylene glycol mono- or di-methacrylate is polyethylene glycol monomethyacrylate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-10-31 | 1998-05-02 | 1998-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-31 | 2002-05-02 | 2002-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-31 | 2006-05-02 | 2006-11-01 | $7700.00 | Window Closed / Lapsed |