Copolymers useful for gelling acids
AssigneeBaker Hughes Incorporated
InventorsDavid J. Poelker, JoAnn McMahon, Dee Harkey
Life of this patent
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Abstract
Disclosed is a copolymer useful for preparing acid gels comprising a copolymer having a copolymer backbone, the copolymer having a general formula: wherein: (a) A is an H or other terminating group; (b) R1 is an OH or NH2; (c) R2 is an O or NH; (d) Z is an integer having a value of from 1 to 4; (e) X and Y are present in a ratio (X:Y) of from 3:2 to 4:1; (f) structures I and II are present as blocks or randomly distributed along the copolymer backbone; and wherein the copolymer has a molecular weight of from about 1,000,000 to about 10,000,000.
Claims14
A method for fracturing a subterranean formation, the subterranean formation being in fluid communication with the surface through a well bore, comprising:
- (a) creating a fracture in a subterranean formation;
- and
- (b) injecting into the fracture an etching agent, wherein the etching agent includes a gelled acid comprising an acid gelled using a copolymer having a backbone, the organic component of the gelled acid having the general formula:
- wherein:
- (a) A is an H or other terminating group;
- (b) R1 is an OH or NH2;
- (c) R2 is an O or NH;
- (d) Z is an integer having a value of from 1 to 4;
- (e) X and Y are present in a ratio (X:Y) of from 3:2 to 4:1;
- (f) structures I and II are present as blocks or randomly distributed along the copolymer backbone;
- (g) D−is an anion of a mineral acid;
- and
- wherein the copolymer has a molecular weight of from about 1,000,000 to about 10,000,000.
Dependencies are inferred from the claim text.