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Patent US5076361A successfully refreshed from Google Patents.
US5076361A
Expired / Lapsed
US
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Gel method for decreasing permeability around a wellbore
Assignee: Texaco Inc
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Filing: 1990-09-07
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Granted: 1991-12-31
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Expires: 2010-09-07
Abstract
Abstract The invention is a method for decreasing formation permeability in an underground formation around a wellbore by injecting an aqueous fresh water solution comprising about 0.9% to about 3.0% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000 and about 0.4% to about 3.0% by weight of an alkali metal dodecyl sulfate in the ratio of about 3:1 to about 1:1.5 of cellulose to sulfate, said formation must contain a connate brine having a salinity greater than about 20,000 ppm TDS, or an injected brine having a salinity greater than about 20,000 ppm TDS to mix and react with the aqueous solution to form a gel. The invention is also a method for forming a high viscosity gel by mixing hydroxy propyl cellulose, alkali metal dodecyl sulfate and sufficient salinity.
Inventors
- 👤 Douglas G. Naae
- 👤 Lawrence E. Whittington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:53
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/86; C09K8/88; C09K8/90
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
101 words
A method for decreasing formation permeability in an underground formation around a wellbore, comprising: injecting an aqueous fresh water solution into the formation surrounding a wellbore, said aqueous solution comprising about 0.6% to about 3.0% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000, and about 0.4% to about 3.0% by weight of an alkali metal dodecyl sulfate, in the ratio of about 3:1 to about 1:1.5 of cellulose to sulfate, and said formation containing connate brine of a salinity greater than about 20,000 ppm TDS to react with said solution to form a gel.
Claim 2
Independent Claim
101 words
A method for decreasing formation permeability in an underground formation around a wellbore, comprising: injecting an aqueous fresh water solution into the formation surrounding a wellbore, said aqueous solution comprising about 0.6% to about 3.0% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000, and about 0.4% to about 3.0% by weight of an alkali metal dodecyl sulfate, in the ratio of about 3:1 to about 1:1.5 of cellulose to sulfate, and said formation containing connate brine of a salinity greater than about 20,000 ppm TDS to react with said solution to form a gel.
Claim 3
Dependent Claim
30 words
The method of claim 1, further comprising injecting a brine having a salinity greater than about 20,000 ppm TDS into the formation surrounding the wellbore after injecting said aqueous solution.
Claim 4
Dependent Claim
26 words
The method of claim 2, further comprising injecting a second slug of said solution into the formation surrounding the wellbore after the injection of the brine.
Claim 5
Dependent Claim
50 words
The method of claim 1, further comprising adding about 0.1% to about 2% by weight of a solubilizer to said aqueous solution to prevent phase separation from said aqueous solution of the alkali metal dodecyl sulfate when the connate brine has a divalent ion concentration greater than about 1500 ppm.
Claim 6
Dependent Claim
13 words
The method of claim 4, wherein the solubilizer is an alcohol ethoxy sulfate.
Claim 7
Independent Claim
95 words
A method for decreasing formation permeability in an underground formation around a wellbore, comprising: injecting an aqueous fresh water solution into the formation surrounding a wellbore, said aqueous solution comprising about 0.6% to about 3.0% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000, about 0.4% to about 3.0% by weight of an alkali metal dodecyl sulfate, in the ratio of about 3:1 to about 1:1.5 of cellulose to sulfate; and injecting a brine having a salinity greater that about 20,000 ppm TDS into the formation surrounding the wellbore.
Claim 8
Independent Claim
95 words
A method for decreasing formation permeability in an underground formation around a wellbore, comprising: injecting an aqueous fresh water solution into the formation surrounding a wellbore, said aqueous solution comprising about 0.6% to about 3.0% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000, about 0.4% to about 3.0% by weight of an alkali metal dodecyl sulfate, in the ratio of about 3:1 to about 1:1.5 of cellulose to sulfate; and injecting a brine having a salinity greater that about 20,000 ppm TDS into the formation surrounding the wellbore.
Claim 9
Dependent Claim
27 words
The method of claim 6, further comprising injecting a second slug of said aqueous solution into the formation surrounding the wellbore after the injection of the brine.
Claim 10
Dependent Claim
21 words
The method of claim 6, further comprising repeating the injection of said aqueous solution and said brine in an alternating fashion.
Claim 11
Dependent Claim
34 words
The method of claim 6, further comprising isolating the portion of the formation wherein it is desired to decrease permeability with packers in the wellbore, and injecting into that isolated portion of the formation.
Claim 12
Dependent Claim
15 words
The method of claim 6, wherein the alkali metal dodecyl sulfate is sodium dodecyl sulfate.
Claim 13
Dependent Claim
18 words
The method of claim 6, wherein the ratio of cellulose to sulfate is about 2:1 to about 1:1.
Claim 14
Dependent Claim
46 words
The method of claim 6, further comprising adding about 0.1% to about 2% by weight of a solubilizer to prevent phase separation from said aqueous solution of the alkali metal dodecyl sulfate when the injected brine has a divalent ion concentration greater than about 1500 ppm.
Claim 15
Dependent Claim
13 words
The method of claim 12, wherein the solubilizer is an alcohol ethoxy sulfate.
Claim 16
Dependent Claim
21 words
The method of claim 6, wherein the concentration of the hydroxy propyl cellulose is about 0.9% to about 1.5% by weight.
Claim 17
Dependent Claim
22 words
The method of claim 6, wherein the concentration of the alkali metal dodecyl sulfate is about 0.5% to about 1.5% by weight.
Claim 18
Dependent Claim
18 words
The method of claim 6, wherein the ratio of cellulose to sulfate is about 2:1 to about 1:1.
Claim 19
Dependent Claim
30 words
The method of claim 6, further comprising injecting a small slug of fresh water between said aqueous solution and said brine to ensure gelation does not occur at a sandface.
Claim 20
Dependent Claim
23 words
The method of claim 6, further comprising flushing the underground formation surrounding the wellbore with fresh water prior to injecting said aqueous solution.
Claim 21
Dependent Claim
52 words
The method of claim 6, further comprising adding about 0.1% to about 2% by weight of a solubilizer to said aqueous solution to prevent phase separation from said aqueous solution of the alkali metal dodecyl sulfate when injected brine or connate brine has a divalent ion concentration greater than about 1,500 ppm.
Claim 22
Dependent Claim
23 words
The method of claim 19, wherein the solubilizer is an alcohol ethoxy sulfate having an ethoxylation level greater than or equal to 2.
Claim 23
Dependent Claim
13 words
The method of claim 20, wherein the solubilizer is sodium lauryl ether sulfate.
Claim 24
Independent Claim
108 words
The method for decreasing formation permeability in an underground formation around a wellbore, comprising: injecting an aqueous fresh water solution into the formation surrounding a wellbore, said aqueous solution comprising about 0.9% to about 1.5% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000 and about 0.5% to about 1.5% by weight of sodium dodecyl sulfate in the ratio of about 2:1 to about 1:1 of cellulose to sulfate; injecting a brine having a salinity greater than about 50,000 ppm TDS into the formation surrounding the wellbore; and repeating the injection of said aqueous solution and said brine in an alternating fashion.
Claim 25
Independent Claim
108 words
The method for decreasing formation permeability in an underground formation around a wellbore, comprising: injecting an aqueous fresh water solution into the formation surrounding a wellbore, said aqueous solution comprising about 0.9% to about 1.5% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000 and about 0.5% to about 1.5% by weight of sodium dodecyl sulfate in the ratio of about 2:1 to about 1:1 of cellulose to sulfate; injecting a brine having a salinity greater than about 50,000 ppm TDS into the formation surrounding the wellbore; and repeating the injection of said aqueous solution and said brine in an alternating fashion.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
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