US4169797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for acidizing subterranean formations
Assignee: Phillips Petroleum Co
•
Filing: 1977-10-27
•
Granted: 1979-10-02
•
Expires: 1997-10-27
Abstract
Abstract Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations, and methods of using said compositions in acidizing operation, are provided. Said compositions comprise water, a water-soluble cellulose ether, an acid, a water-soluble compound of a polyvalent metal wherein the metal can be reduced to a lower polyvalent valence state and cause gelation of the water containing said cellulose ether and said acid, and a reducing agent capable of reducing said metal and causing said gelation.
Inventors
- 👤 Chester C. Johnston, Jr.
- 👤 Brent J. Bertus
- 👤 James E. Hessert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:54
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/76; Y; Y10; Y10S; Y10S507/00; Y10S507/903; Y10S507/922; Y10S507/923; Y10S507/933
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
297 words
A gelled acidic composition, suitable for matrix-acidizing or fracture-acidizing of a subterranean formation, comprising: water; a water-thickening amount of a water-soluble cellulose ether; an 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 cause gelation of an aqueous dispersion of the components of said composition when the valence of at least a portion of said metal is reduced to said lower valence state, said compound being selected from the group consisting of potassium permanganate, sodium permanganate, ammonium chromate, ammonium dichromate, the alkali metal chromates, the alkali metal dichromates and chromium trioxide; 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 cause said gelation; and an amount within the range of from 1 to 12 weight percent, based on the total weight of the composition of a non-oxidizing acid which is capable of reacting with a significant amount of the acid-soluble components of said formation, said non-oxidizing acid being selected from the group consisting of hydrochloric acid, sulfuric acid and mixtures thereof; said cellulose ether, said polyvalent metal compound, said reducing agent, and said acid, in the amounts used, being sufficiently compatible with each other in an aqueous dispersion thereof to permit said gelation and thus form a said composition having sufficient stability to degeneration by the heat of said formation to permit good penetration of said composition into said formation and the maintenance of said composition in said formation in contact therewith for a period of time sufficient for the acid in said composition to significantly react with the acid-soluble components of said formation and stimulate the production of hydrocarbons therefrom.
Claim 2
Dependent Claim
297 words
A gelled acidic composition, suitable for matrix-acidizing or fracture-acidizing of a subterranean formation, comprising: water; a water-thickening amount of a water-soluble cellulose ether; an 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 cause gelation of an aqueous dispersion of the components of said composition when the valence of at least a portion of said metal is reduced to said lower valence state, said compound being selected from the group consisting of potassium permanganate, sodium permanganate, ammonium chromate, ammonium dichromate, the alkali metal chromates, the alkali metal dichromates and chromium trioxide; 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 cause said gelation; and an amount within the range of from 1 to 12 weight percent, based on the total weight of the composition of a non-oxidizing acid which is capable of reacting with a significant amount of the acid-soluble components of said formation, said non-oxidizing acid being selected from the group consisting of hydrochloric acid, sulfuric acid and mixtures thereof; said cellulose ether, said polyvalent metal compound, said reducing agent, and said acid, in the amounts used, being sufficiently compatible with each other in an aqueous dispersion thereof to permit said gelation and thus form a said composition having sufficient stability to degeneration by the heat of said formation to permit good penetration of said composition into said formation and the maintenance of said composition in said formation in contact therewith for a period of time sufficient for the acid in said composition to significantly react with the acid-soluble components of said formation and stimulate the production of hydrocarbons therefrom.
Claim 3
Dependent Claim
92 words
A composition according to claim 1 wherein: the amount of said cellulose ether is within the range of from 0.01 to about 5 weight percent based upon the total weight of said composition; the amount of said polyvalent metal compound is within the range of from 0.05 to 30 weight percent based upon the weight of said cellulose ether; and the amount of said reducing agent is within the range of from 0.1 to about 200 percent of the stoichiometric amount required to reduce said polyvalent metal to said lower valence state.
Claim 4
Dependent Claim
14 words
A composition according to claim 1 wherein said cellulose ether is a carboxymethyl cellulose.
Claim 5
Dependent Claim
14 words
A composition according to claim 2 wherein: said cellulose ether is a carboxymethyl cellulose.
Claim 6
Dependent Claim
101 words
A composition according to claim 4 wherein: said cellulose ether is sodium carboxymethyl cellulose and the amount thereof is within the range of from about 0.1 to about 1.5 weight percent; said polyvalent metal compound is sodium dichromate or potassium dichromate; said acid is aqueous hydrochloric acid and the amount thereof is sufficient to provide an amount of HCl within the range of from about 1 to about 10 weight percent, based on the total weight of said composition; and said reducing agent is selected from the group consisting of sodium or potassium bisulfite, sodium or potassium iodide, thiourea, and thioacetamide.
Claim 7
Independent Claim
323 words
A method for preparing a gelled acidic composition, suitable for matrix-acidizing or fracture-acidizing of a subterranean formation, which method comprises: dispersing a water-thickening amount of a water-soluble cellulose ether in water; adding to said water containing said cellulose ether an amount within the range of from 1 to 12 weight percent, based on the total weight of the composition of a non-oxidizing acid which is capable of reacting with a significant amount of the acid-soluble components of said formation, said non-oxidizing acid being selected from the group consisting of hydrochloric acid, sulfuric acid, and mixtures thereof; then adding to said water an 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 cause gelation of an aqueous dispersion of the compounds of said composition when the valence of at least a portion of said metal is reduced to said lower valence state, said compound being selected from the group consisting of potassium permanganate, sodium permanganate, ammonium chromate, ammonium dichromate, the alkali metal chromates, the alkali metal dichromates and chromium trioxide; and then adding to said water 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 cause said gelation; said cellulose ether, said polyvalent metal compound, said reducing agent, and said acid, in the amounts used, being sufficiently compatible with each other in an aqueous dispersion thereof to permit said gelation and thus form a said composition having sufficient stability to degeneration by the heat of said formation to permit good penetration of said composition into said formation and the maintenance of said composition in said formation in contact therewith for a period of time sufficient for the acid in said composition to significantly react with the acid-soluble components of said formation and stimulate the production of hydrocarbons therefrom.
Claim 8
Independent Claim
323 words
A method for preparing a gelled acidic composition, suitable for matrix-acidizing or fracture-acidizing of a subterranean formation, which method comprises: dispersing a water-thickening amount of a water-soluble cellulose ether in water; adding to said water containing said cellulose ether an amount within the range of from 1 to 12 weight percent, based on the total weight of the composition of a non-oxidizing acid which is capable of reacting with a significant amount of the acid-soluble components of said formation, said non-oxidizing acid being selected from the group consisting of hydrochloric acid, sulfuric acid, and mixtures thereof; then adding to said water an 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 cause gelation of an aqueous dispersion of the compounds of said composition when the valence of at least a portion of said metal is reduced to said lower valence state, said compound being selected from the group consisting of potassium permanganate, sodium permanganate, ammonium chromate, ammonium dichromate, the alkali metal chromates, the alkali metal dichromates and chromium trioxide; and then adding to said water 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 cause said gelation; said cellulose ether, said polyvalent metal compound, said reducing agent, and said acid, in the amounts used, being sufficiently compatible with each other in an aqueous dispersion thereof to permit said gelation and thus form a said composition having sufficient stability to degeneration by the heat of said formation to permit good penetration of said composition into said formation and the maintenance of said composition in said formation in contact therewith for a period of time sufficient for the acid in said composition to significantly react with the acid-soluble components of said formation and stimulate the production of hydrocarbons therefrom.
Claim 9
Dependent Claim
92 words
A method according to claim 6 wherein: the amount of said cellulose ether is within the range of from 0.01 to about 5 weight percent based upon the total weight of said composition; the amount of said polyvalent metal compound is within the range of from 0.05 to 30 weight percent based upon the weight of said cellulose ether; and the amount of said reducing agent is within the range of from 0.1 to about 200 percent of the stoichiometric amount required to reduce said polyvalent metal to said lower valence state.
Claim 10
Dependent Claim
14 words
A method according to claim 7 wherein: said cellulose ether is a carboxymethyl cellulose.
Claim 11
Dependent Claim
101 words
A method according to claim 8 wherein: said cellulose ether is sodium carboxymethyl cellulose and the amount thereof is within the range of from about 0.1 to about 1.5 weight percent; said polyvalent metal compound is sodium dichromate or potassium dichromate; said acid is aqueous hydrochloric acid and the amount thereof is sufficient to provide an amount of HCl within the range of from about 1 to about 10 weight percent, based on the total weight of said composition; and said reducing agent is selected from the group consisting of sodium or potassium bisulfite, sodium or potassium iodide, thiourea, and thioacetamide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-01 | 1983-04-02 | 1983-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-01 | 1987-04-02 | 1987-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-01 | 1991-04-02 | 1991-10-02 | $7700.00 | Window Closed / Lapsed |