US4451389A
Expired / Lapsed
US
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Aqueous gels
Assignee: Drilling Specialties Co
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Filing: 1982-01-28
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Granted: 1984-05-29
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Expires: 2002-01-28
Abstract
Abstract Carboxymethylhydroxyethyl cellulose in aqueous brine solutions is gelled by the addition of an alkaline earth metal hydroxide such as calcium hydroxide. The gelled compositions have utility as water diversion agents, pusher fluids, fracturing fluids, drilling muds, work-over fluids, and completion fluids.
Inventors
- 👤 Elmer E. Clear
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:10
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588; C09K8/02; C09K8/04; C09K8/06; C09K8/08; C09K8/10; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/514; C09K8/60; C09K8/62; C09K8/66; C09K8/68; C09K8/84; C09K8/86; C09K8/88; C09K8/90; Y; Y10; Y10S; Y10S507/00; Y10S507/922; Y10S507/925
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
73 words
A gelled aqueous brine composition which comprises (a) an aqueous brine solution having at least 1,000 ppm divalent cations, (b) a water thickening amount of carboxymethylhydroxyethyl cellulose (CHMEC) characterized by a degree of substitution (DS) ranging from about 0.1 to about 1 and a molar substitution (MS) ranging from about 1 to about 4, and (c) an amount of an alkaline earth metal hydroxide sufficient to cause gelation and form said gelled composition.
Claim 2
Dependent Claim
73 words
A gelled aqueous brine composition which comprises (a) an aqueous brine solution having at least 1,000 ppm divalent cations, (b) a water thickening amount of carboxymethylhydroxyethyl cellulose (CHMEC) characterized by a degree of substitution (DS) ranging from about 0.1 to about 1 and a molar substitution (MS) ranging from about 1 to about 4, and (c) an amount of an alkaline earth metal hydroxide sufficient to cause gelation and form said gelled composition.
Claim 3
Dependent Claim
33 words
A composition according to claim 1 wherein (b) is characterized by a degree of substitution ranging from about 0.2 to about 0.5 and a molar substitution ranging from about 2 to about 3.
Claim 4
Dependent Claim
36 words
A composition according to claim 1 wherein the amount of (b) present ranges from about 0.5 to about 4 lbs/barrel and the amount of (c) present ranges from about 0.25 to about 4 lbs/barrel of solution.
Claim 5
Dependent Claim
11 words
A composition according to claim 1 wherein (c) is calcium hydroxide.
Claim 6
Dependent Claim
38 words
A composition according to claim 4 wherein the amounts of (b) present range from about 2 to about 3 lbs/barrel of solution and the amount of (c) present ranges from about 0.5 to about 3 lbs/barrel of solution.
Claim 7
Independent Claim
68 words
A method of preparing a thickened and gelled aqueous brine solution which comprises mixing an aqueous brine having at least 1,000 ppm divalent cations with a water thickening amount of carboxymethylhydroxyethyl cellulose characterized by a degree of substitution (DS) ranging from about 0.1 to about 1 and a molar substitution (MS) ranging from about 1 to about 4 and a gelling amount of an alkaline earth metal hydroxide.
Claim 8
Independent Claim
68 words
A method of preparing a thickened and gelled aqueous brine solution which comprises mixing an aqueous brine having at least 1,000 ppm divalent cations with a water thickening amount of carboxymethylhydroxyethyl cellulose characterized by a degree of substitution (DS) ranging from about 0.1 to about 1 and a molar substitution (MS) ranging from about 1 to about 4 and a gelling amount of an alkaline earth metal hydroxide.
Claim 9
Dependent Claim
39 words
A method according to claim 6 wherein the amount of carboxymethylhydroxyethyl cellulose ranges from about 0.5 to about 4 lbs/barrel of solution and the amount of alkaline earth metal ranges from about 0.25 to about 4 lbs/barrel of solution.
Claim 10
Dependent Claim
15 words
A method according to claim 6 wherein the alkaline earth metal hydroxide is calcium hydroxide.
Claim 11
Dependent Claim
34 words
A method according to claim 8 wherein the amount of carboxymethylhydroxyethyl cellulose ranges from about 2 to about 3 lbs/barrel and the amount of calcium hydroxide ranges from about 0.5 to about 3 lbs/barrel.
Claim 12
Dependent Claim
33 words
A method according to claim 6 wherein (b) is characterized by a degree of substitution ranging from about 0.2 to about 0.5 and a molar substitution ranging from about 2 to about 3.
Claim 13
Dependent Claim
90 words
A gelled aqueous brine composition which comprises (a) an aqueous hard brine comprising on the order of 1,000 to 16,000 ppm divalent cations and a total dissolved solids (TDS) level in the range of 100,000 to 300,000 ppm, (b) about 0.5 to about 4 lbs./barrel brine of carboxymethylhydroxyethylcellulose (CMHEC) characterized by a degree of substitution (DS) ranging from about 0.1 to about 1 and a molar substitution (MS) ranging from about 1 to about 4, and (c) about 0.25 to about 4 lbs./barrel brine of an alkaline earth metal hydroxide.
Claim 14
Dependent Claim
90 words
A gelled aqueous brine composition which comprises (a) an aqueous hard brine comprising on the order of 1,000 to 16,000 ppm divalent cations and a total dissolved solids (TDS) level in the range of 100,000 to 300,000 ppm, (b) about 0.5 to about 4 lbs./barrel brine of carboxymethylhydroxyethylcellulose (CMHEC) characterized by a degree of substitution (DS) ranging from about 0.1 to about 1 and a molar substitution (MS) ranging from about 1 to about 4, and (c) about 0.25 to about 4 lbs./barrel brine of an alkaline earth metal hydroxide.
Claim 15
Dependent Claim
11 words
A composition according to claim 11 wherein (c) is calcium hydroxide.
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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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |