Patent US2281419A successfully refreshed from Google Patents.
US3845822A
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Plugging or sealing fractures in formations
Assignee: Phillips Petroleum Co
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Filing: 1973-06-21
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Granted: 1974-11-05
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Expires: 1993-06-21
Abstract
Abstract Improvements in plugging of fractures in formations are accomplished by the use of aqueous gels prepared from water and cellulose ethers, e.g., carboxymethyl cellulose.
Inventors
- 👤 R Clampitt
- 👤 J Hessert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:48
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; B; B01; B01J; B01J19/00; B01J19/06; C09K8/58; C09K8/588; C09K8/80; E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/261
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
148 words
A METHOD FOR PLUGGING A FRACTURE IN A FORMATION, WHICH METHOD COMPRISES: INTRODUCING ITNO SAID FRACTURE A FLUID COMPRISING AN AQUEOUS GEL, SAID GEL COMPRISING WATER TO WHICH THERE HAS BEEN ADDED A WATER-THICKENING AMOUNT OF WATER-SOLUBLE CELLULOSE ETHER, A SENSIBLE AMOUNT OF A WATER-SOLUBLE COMPOUND OF A POLYVALENT METAL WHEREIN THE METAL PRESENT IS CAPABLE OF BEING REDUCED TO A LOWER POLYVALENT VALENCE STATE AND WHICH IS SUFFICIENT TO GEL SAID WATER WHEN THE VALENCE OF AT LEAST A PORTION OF SAID METAL IS REDUCED TO SAID LOWER VALENCE STATE, AND AN AMOUNT OF A WATER-SOLUBLE REDUCING AGENT WHICH IS EFFECTIVE TO REDUCE AT LEAST A PORTION OF SAID METAL TO SAID LOWER VALENCE STATE; AND MAINTAINING SAID GEL IN SAID FRACTURE IN A QUIESCENT STATE FOR A PERIOD OF TIME SUFFICIENT FOR SAID GEL TO DEVELOP SUFFICIENT GEL STRENGTH TO REMAIN IN PLACE IN SAID FRACTURE.
Claim 2
Independent Claim
148 words
A METHOD FOR PLUGGING A FRACTURE IN A FORMATION, WHICH METHOD COMPRISES: INTRODUCING ITNO SAID FRACTURE A FLUID COMPRISING AN AQUEOUS GEL, SAID GEL COMPRISING WATER TO WHICH THERE HAS BEEN ADDED A WATER-THICKENING AMOUNT OF WATER-SOLUBLE CELLULOSE ETHER, A SENSIBLE AMOUNT OF A WATER-SOLUBLE COMPOUND OF A POLYVALENT METAL WHEREIN THE METAL PRESENT IS CAPABLE OF BEING REDUCED TO A LOWER POLYVALENT VALENCE STATE AND WHICH IS SUFFICIENT TO GEL SAID WATER WHEN THE VALENCE OF AT LEAST A PORTION OF SAID METAL IS REDUCED TO SAID LOWER VALENCE STATE, AND AN AMOUNT OF A WATER-SOLUBLE REDUCING AGENT WHICH IS EFFECTIVE TO REDUCE AT LEAST A PORTION OF SAID METAL TO SAID LOWER VALENCE STATE; AND MAINTAINING SAID GEL IN SAID FRACTURE IN A QUIESCENT STATE FOR A PERIOD OF TIME SUFFICIENT FOR SAID GEL TO DEVELOP SUFFICIENT GEL STRENGTH TO REMAIN IN PLACE IN SAID FRACTURE.
Claim 3
Dependent Claim
83 words
A method according to claim 1 wherein said aqueous gel comprises water to which therE has been added: from 0.2 to 1.5 weight percent of said cellulose ether, based upon the weight of said water; from 0.05 to 60 weight percent of said polyvalent metal compound, based upon the weight of said cellulose ether; and from 0.1 to at least about 200 percent of the stoichiometric amount of said reducing agent required to reduce said polyvalent metal to said lower polyvalent valence state.
Claim 4
Dependent Claim
15 words
A method according to claim 2 wherein said cellulose ether is a carboxymethyl cellulose ether.
Claim 5
Dependent Claim
67 words
A method according to claim 3 wherein: said compound of a polyvalent metal is a compound of chromium wherein the valence of the chromium is +6 and the valence of at least a portion of said chromium is reduced to +3; and said chromium compound is selected from the group consisting of ammonium chromate, ammonium dichromate, the alkali metal chromates and dichromates, chromium trioxide, and mixtures thereof.
Claim 6
Dependent Claim
49 words
A method according to claim 4 wherein said reducing agent is selected from the group consisting of hydroquinone, sodium sulfide, hydrogen sulfide, sodium hydrosulfite, sodium metabisulfite, potassium sulfite, sodium bisulfite, potassium metabisulfite, sodium sulfite, sodium thiosulfate, ferrous sulfate, ferrous chloride, p-hydrazinobenzoic acid, hydrazine phosphite, hydrazine dihydrochloride, and mixtures thereof.
Claim 7
Dependent Claim
43 words
A method according to claim 2 wherein: said cellulose ether is sodium carboxymethyl cellulose; said polyvalent metal compound is sodium dichromate; and said reducing agent is selected from the group consisting of sodium bisulfite, sodium metabisulfite, sodium hydrosulfite, sodium thiosulfate, and mixtures thereof.
Claim 8
Dependent Claim
62 words
A method according to claim 2 wherein there has also been added to said water, and is thus incorporated into said gel, a finely divided solid capable of causing, and in an amount thereof within the range of from 0.05 to 2 pounds per gallon of said water which is sufficient to cause, an increase in the gel strength of said gel.
Claim 9
Dependent Claim
14 words
A method according to claim 7 wherein said finely divided solid comprises diatomaceous earth.
Claim 10
Dependent Claim
15 words
A method according to claim 8 wherein said cellulose ether is a carboxymethyl cellulose ether.
Claim 11
Dependent Claim
99 words
A method according to claim 9 wherein: said cellulose ether is an alkali metal carboxymethyl cellulose ether; said compound of a polyvalent metal is a compound of chromium wherein the valence of the chromium is +6 and the valence of at least a portion of said chromium is reduced to +3, and said chromium compound is selected from the group consisting of ammonium chromate, ammonium dichromate, the alkali metal chromates and dichromates, chromium trioxide, and mixtures thereof; and said reducing agent is selected from the group consisting of sodium bisulfite, sodium metabisulfite, sodium hydrosulfite, sodium thiosulfate, and mixtures thereof.
Claim 12
Dependent Claim
22 words
A method according to claim 10 wherein: said cellulose ether is sodium carboxymethyl cellulose; and said polyvalent metal compound is sodium dichromate.
Claim 13
Dependent Claim
61 words
A method according to claim 1 wherein: said formation is susceptible to attack by an acid; a slug of an acid is injected into said fracture prior to the injection of said gel; a slug of flush water is injected into said fracture subsequent to the injection of said acid; and said gel is injected subsequent to said slug of water.
Claim 14
Dependent Claim
25 words
A method according to claim 12 wherein said acid is selected from the group consisting of hydrochloric acid, formic acid, acetic acid, and mixtures thereof.
Claim 15
Dependent Claim
84 words
A method according to claim 13 wherein said aqueous gel comprises water to which there has been added: from 0.2 to about 1.5 weight percent of said cellulose ether, based upon the weight of said water; from 0.5 to 30 weight percent of said polyvalent metal compound, based upon the weight of said cellulose ethers; and fRom 0.5 to at least about 150 percent of the stoichiometric amount of said reducing agent required to reduce said polyvalent metal to said lower polyvalent valence state.
Claim 16
Dependent Claim
26 words
A method according to claim 14 wherein: said cellulose ether is an alkali metal carboxymethyl cellulose; and said polyvalent metal compound is an alkali metal dichromate.
Claim 17
Dependent Claim
51 words
A method according to claim 15 wherein: said cellulose ether is sodium carboxymethyl cellulose; said polyvalent metal compound is sodium dichromate; said reducing agent is selected from the group consisting of sodium hydrosulfite, sodium thiosulfate, sodium bisulfite, sodium metabisulfite, and mixtures thereof; and said acid comprises a solution of hydrochloric acid.
Claim 18
Dependent Claim
46 words
A method according to claim 1 wherein there has also been added to said water, and is thus incorporated into said gel, a finely divided solid capable of causing, and in an amount thereof sufficient to cause, an increase in the gel strength of said gel.
Claim 19
Dependent Claim
14 words
A method according to claim 17 wherein said finely divided solid comprises diatomaceous earth.
Claim 20
Independent Claim
187 words
A method of plugging a fracture in a subterranean porous formation penetrated by a wellbore, which method comprises, in combination, the steps of: A. forming a base plugging fluid by adding to a given quantity of water from 0.2 to 1.5 weight percent of a water-soluble cellulose ether, based on the weight of said water; B. adding to said base fluid one of (a) from 0.5 to 40 weight percent of a water-soluble compound of chromium wherein the valence of the chromium is +6 and which is sufficient to gel said water when the valence of at least a portion of said chromium is reduced from +6 to +3, or (b) from 0.5 to at least about 150 percent of the stoichiometric amount of a water-soluble reducing agent which is effective to reduce the valence of said chromium from +6 to +3; C. pumping a slug of said plugging fluid of step (B) down said well and into said fracture; and D. during said pumping adding to said plugging fluid the other of said reagents (a) and (b) which was not added thereto in said step (B).
Claim 21
Independent Claim
187 words
A method of plugging a fracture in a subterranean porous formation penetrated by a wellbore, which method comprises, in combination, the steps of: A. forming a base plugging fluid by adding to a given quantity of water from 0.2 to 1.5 weight percent of a water-soluble cellulose ether, based on the weight of said water; B. adding to said base fluid one of (a) from 0.5 to 40 weight percent of a water-soluble compound of chromium wherein the valence of the chromium is +6 and which is sufficient to gel said water when the valence of at least a portion of said chromium is reduced from +6 to +3, or (b) from 0.5 to at least about 150 percent of the stoichiometric amount of a water-soluble reducing agent which is effective to reduce the valence of said chromium from +6 to +3; C. pumping a slug of said plugging fluid of step (B) down said well and into said fracture; and D. during said pumping adding to said plugging fluid the other of said reagents (a) and (b) which was not added thereto in said step (B).
Claim 22
Dependent Claim
37 words
A method according to claim 19 wherein said plugging fluid is introduced into said fracture at a rate and a pressure sufficient to open said fracture and maintain same open during the introduction of said plugging fluid.
Claim 23
Dependent Claim
81 words
A method according to claim 19 wherein: said cellulose ether is a carboxymethyl cellulose ether; said chromium compound is selected from the group consisting of ammonium chromate, ammonium dichromate, the alkali metal chromates and dichromates, chromium trioxide, and mixtures thereof; and said reducing agent is selected from the group consisting of hydroquinone, sodium sulfide, sodium hydrosulfite, sodium metabisulfite, potassium sulfite, sodium bisulfite, potassium metabisulfite, sodium sulfite, sodium thiosulfate, ferrous sulfate, ferrous chloride, p-hydrazinobenzoic acid, hydrazine phosphite, hydrazine dihydrochloride, and mixtures thereof.
Claim 24
Dependent Claim
25 words
A method according to claim 19 wherein: said cellulose ether is an alkali metal carboxymethyl cellulose; and said chromium compound is an alkali metal dichromate.
Claim 25
Dependent Claim
42 words
A method according to claim 22 wherein: said cellulose ether is sodium carboxymethyl cellulose; said chromium compound is sodium dichromate; and said reducing agent is selected from the group consisting of sodium thiosulfate, sodium hydrosulfite, sodium bisulfite, sodium metabisulfite, and mixtures thereof.
Claim 26
Dependent Claim
77 words
A method according to claim 22 wherein said formation is susceptible to attack by an acid, and said method comprises in further combination the steps of: injecting a slug of an acid into said fracture prior to the injection of said plugging fluid as in said steps (C) and (D); injecting a slug of flush water into said fracture subsequent to introducing said acid; and then injecting said plugging field as in said steps (C) and (D).
Claim 27
Dependent Claim
99 words
A method according to claim 24 wherein: said cellulose ether is a carboxymethyl cellulose ether; said chromium compound is selected from the group consisting of ammonium chromate, ammonium dichromate, the alkali metal chromates and dichromates, chromium trioxide, and mixtures thereof; said reducing agent is selected from the group consisting of hydroquinone, sodium sulfide, sodium hydrosulfite, sodium metabisulfite, potassium sulfite, sodium bisulfite, potassium metabisulfite, sodium sulfite, sodium thiosulfate, ferrous sulfate, ferrous chloride, p-hydrazinobenzoic acid, hydrazine phosphite, hydrazine dihydrochloride, and mixtures thereof; and said acid is selected from the group consisting of hydrochloric acid, formic acid, acetic acid, and mixtures thereof.
Claim 28
Dependent Claim
36 words
A method according to claim 25 wherein: said cellulose ether is sodium carboxymethyl cellulose; said chromium compound is sodium dichromate; and said reducing agent is sodium thiosulfate, sodium hydrosulfite, sodium bisulfite, sodium metabisulfite, and mixtures thereof.
Claim 29
Dependent Claim
15 words
A method according to claim 26 wherein said acid comprises a solution of hydrochloric acid.
Claim 30
Dependent Claim
60 words
A method according to claim 19 wherein in said step (D), there is also added to said plugging fluid a finely divided solid capable of causing, and in an amount thereof within the range of from 0.1 to 1.5 pounds per gallon of said water which is sufficient to cause, an increase in the gel strength of the resulting gel.
Claim 31
Dependent Claim
42 words
A method according to claim 28 wherein: said cellulose ether is sodium carboxymethyl cellulose; said chromium compound is sodium dicharomate; and said reducing agent is selected from the group consisting of sodium thiosulfate, sodium hydrosulfite, sodium bisulfite, sodium metabisulfite, and mixtures thereof.
Claim 32
Dependent Claim
14 words
A method according to claim 29 wherein said finely divided solid is diatomaceous earth.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |