Patent ID: 7759292

Claim:
A method of acidizing a subterranean formation penetrated by a well bore comprising: providing a permeability-modifying aqueous treatment fluid comprising: a relative permeability modifier comprising a hydrophobically modified water-soluble polymer formed from: a reaction comprising a hydrophilic polymer and a hydrophobic compound, wherein the hydrophobically modified water-soluble polymer formed from the reaction has a molecular weight in the range of about 100,000 to about 10,000,000, or a polymerization reaction comprising a hydrophilic monomer and a hydrophobically modified hydrophilic monomer, wherein the hydrophobically modified water-soluble polymer formed from the polymerization reaction has a molecular weight in the range of about 250,000 to about 3,000,000, wherein the hydrophobically modified water-soluble polymer comprises a polymer backbone comprising polar heteroatoms and a hydrophobic branch that comprises an organic acid derivative selected from the group consisting of: an anhydride of octenyl succinic acid; an ester of octenyl succinic acid; an amide of octenyl succinic acid; an anhydride of dodecenyl succinic acid; an ester of dodecenyl succinic acid; and an amide of dodecenyl succinic acid, and wherein the hydrophobically modified water-soluble polymer reduces the permeability of the subterranean formation to an aqueous-based fluid; providing an acidizing treatment fluid comprising an acid; injecting the permeability-modifying aqueous treatment fluid into the subterranean formation; and injecting the acidizing treatment fluid into the subterranean formation.