US3727688A
Expired / Lapsed
US
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Hydraulic fracturing method
Assignee: Phillips Petroleum Co
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Filing: 1972-02-09
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Granted: 1973-04-17
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Expires: 1992-02-09
Abstract
Abstract Improvements in hydraulic fracturing of underground porous formations penetrated by a well bore are accomplished by the use of fracturing fluids comprising a gelled solution of a cellulose ether, e.g., carboxymethyl cellulose.
Inventors
- 👤 R Clampitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:07
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/76; B; B01; B01J; B01J19/00; B01J19/06; C09K8/66; C09K8/68; C09K8/685; C09K8/84; C09K8/86; C09K8/88; C09K8/90; Y; Y10; Y10S; Y10S507/00; Y10S507/903; Y10S507/922
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
83 words
A method according to claim 1 wherein said aqueous gel comprises water to which there has been added: from 0.0025 to 20 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 2
Dependent Claim
15 words
A methOd according to claim 2 wherein said cellulose ether is a carboxymethyl cellulose ether.
Claim 3
Dependent Claim
41 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.
Claim 4
Dependent Claim
32 words
A method according to claim 4 wherein 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 5
Dependent Claim
47 words
A method according to claim 5 wherein 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 6
Dependent Claim
28 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 sodium hydrosulfite.
Claim 7
Dependent Claim
28 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 sodium thiosulfate.
Claim 8
Dependent Claim
49 words
A method according to claim 1 wherein: said formation is susceptible to attack by an acid; a slug of said fracturing fluid comprising said gel is injected into said formation; and a slug of an acid is injected into said formation subsequent to the injection of said fracturing fluid.
Claim 9
Dependent Claim
31 words
A method according to claim 9 wherein a slug of a spacer fluid is injected into said formation after the injection of said fracturing fluid and prior to injecting said acid.
Claim 10
Dependent Claim
25 words
A method according to claim 9 wherein said acid is selected from the group consisting of hydrochloric acid, formic acid, acetic acid, and mixtures thereof.
Claim 11
Dependent Claim
83 words
A method according to claim 11 wherein said aqueous gel comprises water to which there has been added: from 0.025 to 1 weight percent of said cellulose ether, based upon the weight of said water; from 0.5 to 40 weight percent of said polyvalent metal compound, based upon the weight of said cellulose ether; 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 12
Dependent Claim
26 words
A method according to claim 12 wherein: said cellulose ether is an alkali metal carboxymethyl cellulose; and said polyvalent metal compound is an alkali metal dichromate.
Claim 13
Dependent Claim
39 words
A method according to claim 13 wherein: said cellulose ether is sodium carboxymethyl cellulose; said polyvalent metal compound is sodium dichromate; said reducing agent is sodium hydrosulfite or sodium thiosulfate; and said acid comprises a solution of hydrochloric acid.
Claim 14
Dependent Claim
43 words
A method according to claim 1 wherein the temperature of said formation is greater than about 200* F. and the life-span of said gel is such that it breaks down to a viscosity approaching that of water in less than about 12 hours.
Claim 15
Dependent Claim
50 words
A method according to claim 1 wherein an excessive amount of said gelling agents is used, relative to the amount of said cellulose ether, so that the life-span of said gel is such that it breaks down to a viscosity approaching that of water in less than about 12 hours.
Claim 16
Independent Claim
198 words
A method of fracturing a subterranean porous formation penetrated by a wellbore, which method comprises, in combination, the steps of: A. forming a base fracturing fluid by adding to a given quantity of water from 0.025 to 1 weight percent of a water-soluble cellulose ether, based on the weight of said water; B. adding to said base fracturing 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 base fracturing fluid of step (B) down said well and into said formation under a pressure sufficient to create a fracture in said formation; and D. during said pumping adding to said base fracturing fluid the other of said reagents (a) and (b) which was not added thereto in said step (B).
Claim 17
Dependent Claim
81 words
A method according to claim 17 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 18
Dependent Claim
25 words
A method according to claim 18 wherein: said cellulose ether is an alkali metal carboxymethyl cellulose; and said chromium compound is an alkali metal dichromate.
Claim 19
Dependent Claim
30 words
A method according to claim 19 wherein: said cellulose ether is sodium carboxymethyl cellulose; said chromium compound is sodium dichromate; and said reducing agent is sodium thiosulfate or sodium hydrosulfite.
Claim 20
Dependent Claim
51 words
A method according to claim 17 wherein said formation is susceptible to attack by an acid, and said method comprises in further combination the step of: E. injecting a slug of an acid into said formation subsequent to the injection of said fracturing fluid as in said steps (C) and (D).
Claim 21
Dependent Claim
30 words
A method according to claim 21 wherein a slug of a spacer fluid is injected into said formation after said steps (C) and (D) and prior to said step (E).
Claim 22
Dependent Claim
99 words
A method according to claim 21 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 23
Dependent Claim
30 words
A method according to claim 23 wherein: said cellulose ether is sodium carboxymethyl cellulose; said chromium compound is sodium dichromate; and said reducing agent is sodium thiosulfate or sodium hydrosulfite.
Claim 24
Dependent Claim
38 words
A method according to claim 24 wherein: said cellulose ether is sodium carboxymethyl cellulose; said chromium compound is sodium dichromate; said reducing agent is sodium thiosulfate or sodium hydrosulfite; and said acid comprises a solution of hydrochloric acid.
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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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |