US Patent 7134497 Foamed treatment fluids and associated methods

Foamed treatment fluids comprising water, a gas, and a foaming and foam stabilizing surfactant mixture comprising an alkali salt of an alkyl ether sulfate, wherein the alkali salt of the alkyl ether sulfate comprises an alkali salt of a C6-10 alkyl ether sulfate, and an alkali salt of a C4 alkyl ether sulfate, an alkyl amidopropyl amphoteric surfactant selected from the group consisting of an alkyl amidopropyl hydroxysultaine, an alkyl amidopropyl betaine, and combinations thereof, and an alkyl amidopropyl dimethylamine oxide. Methods comprising providing the foamed treatment fluid and introducing the foamed treatment fluid into a subterranean formation.