Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with relatively high molecular weight acid ammonium salts of an imide of polymaleic anhydride. The salts may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions herein are made in the presence of a reactive solvent, such as a polyalkylene glycol, e.g. polyethylene glycol. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with a polyamine salt of an imide of polymaleic anhydride. The salt may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with relatively high molecular weight acid ammonium salts of an imide of polymaleic anhydride. The salts may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions herein are made in the presence of a reactive solvent, such as a polyalkylene glycol, e.g. polyethylene glycol. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with a polyamine salt of an imide of polymaleic anhydride. The salt may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with relatively high molecular weight polyamine salts of an imide of polymaleic anhydride. The salts may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions herein are made in the presence of a reactive solvent, such as a polyalkylene glycol, e.g. polyethylene glycol. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: Betaine ester quaternary ammonium compounds with reduced toxicity and improved biodegradability are formed by esterification of a haloacetic acid with an alcohol containing at least 4 carbon atoms, followed by quaternization of the halo-acetate with a tertiary amine containing at least 4 carbon atoms. In one non-limiting embodiment the alkyl substituents on the nitrogen of the tertiary amine have at least 2 carbon atoms, and in another non-limiting embodiment are each n-butyl.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with a polyamine salt of an imide of polymaleic anhydride. The salt may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with relatively high molecular weight acid ammonium salts of an imide of polymaleic anhydride. The salts may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions herein are made in the presence of a reactive solvent, such as a polyalkylene glycol, e.g. polyethylene glycol. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: A clayish subterranean formation, such as may be encountered in rock surrounding a well bore during hydrocarbon recovery operations may be stabilized with acid ammonium salt of an imide of polymaleic anhydride. The salt may be unneutralized or partially neutralized. The invention is particularly relevant to hydraulic fracturing fluids used in enhanced oil recovery. The compositions of this invention are more environmentally friendly than some current technology.

Abstract: Betaine ester quaternary ammonium compounds with reduced toxicity and improved biodegradability are formed by esterification of a haloacetic acid with an alcohol containing at least 4 carbon atoms, followed by quaternization of the halo-acetate with a tertiary amine containing at least 4 carbon atoms. In one non-limiting embodiment the alkyl substituents on the nitrogen of the tertiary amine have at least 2 carbon atoms, and in another non-limiting embodiment are each n-butyl.

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.

Abstract: Disclosed is a copolymer useful for preparing acid gels comprising a copolymer having a copolymer backbone, the copolymer having a general formula: 1