Patent ID: 7651982

Claim:
A method of acidizing a subterranean formation comprising: providing a conjugate ion pair of a cationic amine oxide surfactant and an anionic surfactant, wherein: the cationic amine oxide surfactant has the following formula: wherein R 1 , R 2 and R 3 are alkyl, hydroxyalkyl, hydroxyalkyl ether, oxyalkyl, amidoalkyl, alkenyl, aryl or arylalkenyl radicals having non-interfering substituents and having sufficient lengths to provide appropriate surfactancy in an aqueous hydrochloric acid solution and the anionic surfactant comprises at least one anionic surfactant selected from the group consisting of: dodecyl sodium sulfate, dodecyl ammonium sulfate, sodium laureth sulfate, ammonium laureth sulfate, sodium alpha-sulfo methyl laurate, disodium alpha-sulfo laurate, alpha-sulfo methyl cocoate, disodium alpha-sulfa cocoate, dodecylbenzene sulfonic cid, and dodecylbenzene sulfonate salt; preparing the aqueous hydrochloric acid solution comprising water, hydrochloric acid, a cationic hydrochloric acid corrosion inhibitor, and the conjugate ion pair, wherein the conjugate ion pair does not react with the corrosion; and introducing the aqueous hydrochloric acid solution into a subterranean formation that comprises formation oil, wherein the conjugate ion pair reduces the formation of sludge or emulsions resulting from the aqueous hydrochloric acid solution contacting the formation oil.