US5092404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl sulfonate scale inhibitor
Assignee: Marathon Oil Co
•
Filing: 1991-01-22
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Granted: 1992-03-03
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Expires: 2011-01-22
Abstract
Abstract A relatively high molecular weight polyvinyl sulfonate and a process for inhibiting scale deposition, particularly inorganic sulfate such as barium sulfate, wherein an aqueous fluid present in or produced from a subterranean formation is contacted with an aqueous solution having a relatively high molecular weight polyvinyl sulfonate dissolved therein. The aqueous fluid has a pH equal to or less than 6.0 and the polyvinyl sulfonate has a molecular weight of from about 9,000 to about 30,000.
Inventors
- 👤 David O. Falk
- 👤 Frank L. Dormish
- 👤 Phillip M. Beazley
- 👤 Ronald G. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:04
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S166/00; Y10S166/902
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
72 words
A process for inhibiting scale including barium sulfate in aqueous fluid having a pH equal to or less than about 6.0 and being present in or produced from a subterranean formation, the process comprising: contacting said aqueous fluid with an amount of a polyvinyl sulfonate which is effective to inhibit formation of said scale in said aqueous fluid, said polyvinyl sulfonate having a molecular weight of from about 10,500 to about 30,000.
Claim 2
Dependent Claim
72 words
A process for inhibiting scale including barium sulfate in aqueous fluid having a pH equal to or less than about 6.0 and being present in or produced from a subterranean formation, the process comprising: contacting said aqueous fluid with an amount of a polyvinyl sulfonate which is effective to inhibit formation of said scale in said aqueous fluid, said polyvinyl sulfonate having a molecular weight of from about 10,500 to about 30,000.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein said aqueous fluid has a pH of about 4.0 or less.
Claim 4
Dependent Claim
63 words
The process of claim 1 further comprising: injecting an aqueous solution having said polyvinyl sulfonate dissolved therein into said subterranean formation via a well bore in fluid communication with said subterranean formation, said polyvinyl sulfonate being absorbed within a matrix of said subterranean formation, said step of contacting being performed as said polyvinyl sulfonate is desorbed from said matrix into said aqueous fluid.
Claim 5
Dependent Claim
30 words
The process of claim 3 wherein said polyvinyl sulfonate is dissolved into said aqueous solution in an amount of from about 0.4 to about 25 volume percent of the solution.
Claim 6
Dependent Claim
30 words
The process of claim 4 wherein said polyvinyl sulfonate is dissolved into said aqueous solution in an amount of from about 2 to about 20 volume percent of the solution.
Claim 7
Dependent Claim
30 words
The process of claim 5 wherein said polyvinyl sulfonate is dissolved into said aqueous solution in an amount of from about 5 to about 10 volume percent of the solution.
Claim 8
Dependent Claim
22 words
The process of claim 3 further comprising: determining the concentration of polyvinyl sulfonate in said aqueous fluid produced from said subterranean formation.
Claim 9
Dependent Claim
47 words
The process of claim 7 wherein said concentration of polyvinyl sulfonate 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 polyvinyl sulfonate dissolved therein into said subterranean formation.
Claim 10
Dependent Claim
12 words
The process of claim 8 wherein said predetermined value is 50 ppm.
Claim 11
Dependent Claim
12 words
The process of claim 8 wherein said predetermined value is 75 ppm.
Claim 12
Dependent Claim
12 words
The process of claim 8 wherein said predetermined value is 100 ppm.
Claim 13
Dependent Claim
30 words
The process of claim 3 further comprising: injecting a second aqueous solution into said subterranean formation via said well bore to displace said aqueous solution having polyvinyl sulfonate dissolved therein.
Claim 14
Dependent Claim
39 words
The process of claim 12 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 15
Dependent Claim
12 words
The process of claim 3 wherein said aqueous solution is a brine.
Claim 16
Dependent Claim
11 words
The process of claim 14 wherein said brine contains sulfate ions.
Claim 17
Dependent Claim
21 words
The process of claim 3 further comprising: removing deleterious by-products of sulfonation from said aqueous solution prior to said contacting step.
Claim 18
Dependent Claim
20 words
The process of claim 3 wherein said polyvinyl sulfonate has a molecular weight of from about 10,500 to about 25,000.
Claim 19
Dependent Claim
20 words
The process of claim 3 wherein said polyvinyl sulfonate has a molecular weight of from about 12,000 to about 20,000.
Claim 20
Dependent Claim
17 words
The process of claim 3 wherein said polyvinyl sulfonate has a polydispersity of less than about 2.0.
Claim 21
Dependent Claim
14 words
The process of claim 1 wherein said aqueous fluid has carbon dioxide dissolved therein.
Claim 22
Dependent Claim
20 words
The process of claim 1 wherein said polyvinyl sulfonate has a molecular weight of from about 10,500 to about 25,000.
Claim 23
Dependent Claim
20 words
The process of claim 1 wherein said polyvinyl sulfonate has a molecular weight of from about 12,000 to about 20,000.
Claim 24
Dependent Claim
17 words
The process of claim 1 wherein said polyvinyl sulfonate has a polydispersity of less than about 2.0.
Claim 25
Dependent Claim
50 words
The process of claim 1 wherein said step of contacting is performed by metering an aqueous solution having said polyvinyl sulfonate 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 26
Dependent Claim
20 words
The process of claim 24 wherein said polyvinyl sulfonate has a molecular weight of from about 10,500 to about 25,000.
Claim 27
Dependent Claim
20 words
The process of claim 24 wherein said polyvinyl sulfonate has a molecular weight of from about 12,000 to about 20,000.
Claim 28
Dependent Claim
17 words
The process of claim 24 wherein said polyvinyl sulfonate has a polydispersity of less than about 2.0.
Claim 29
Dependent Claim
12 words
The process of claim 24 wherein said aqueous solution is a brine.
Claim 30
Dependent Claim
11 words
The process of claim 28 wherein said brine contains sulfate ions.
Claim 31
Dependent Claim
21 words
The process of claim 24 further comprising: removing deleterious by-products of sulfonation from said aqueous solution prior to said contacting step.
Claim 32
Dependent Claim
14 words
The process of claim 24 wherein said amount is at least about 50 ppm.
Claim 33
Dependent Claim
33 words
The process of claim 1 wherein said process further comprises: injecting said polyvinyl sulfonate into a well bore in fluid communication with said subterranean formation, said polyvinyl sulfonate being encapsulated prior to injection.
Claim 34
Dependent Claim
20 words
The process of claim 32 wherein said polyvinyl sulfonate has a molecular weight of from about 10,500 to about 25,000.
Claim 35
Dependent Claim
20 words
The process of claim 32 wherein said polyvinyl sulfonate has a molecular weight of from about 12,000 to about 20,000.
Claim 36
Dependent Claim
17 words
The process of claim 32 wherein said polyvinyl sulfonate has a polydispersity of less than about 2.0.
Claim 37
Dependent Claim
14 words
The process of claim 32 wherein said amount is at least about 50 ppm.
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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) | 1995-03-03 | 1995-09-02 | 1996-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-03 | 1999-09-02 | 2000-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-03 | 2003-09-02 | 2004-03-03 | $7700.00 | Window Closed / Lapsed |