Patent ID: 7992640

Claim:
A method for treating a subterranean formation comprising: introducing a viscoelastic surfactant gelled fluid into a subterranean formation, where the viscoelastic surfactant gelled fluid comprises: water; at least one viscoelastic surfactant (VES) in an amount effective to increase the viscosity of the water, where the VES is selected from the group consisting of non-ionic, cationic, and zwitterionic surfactants, where the zwitterionic surfactants are selected from the group consisting of dihydroxyl alkyl glycinate, alkyl ampho acetate or propionate, and alkylimino mono- or di-propionates; at least one internal breaker selected from the group consisting of mineral oils, plant oils, fish oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids and combinations thereof; and at least one dicarboxylic acid; treating the subterranean formation with the dicarboxylic acid; and reducing the viscosity of the viscoelastic surfactant gelled fluid with the breaker.