Many methods are provided including a method comprising: providing a surfactant gel having a first viscosity that comprises an aqueous base fluid and a surfactant; placing the surfactant gel into a subterranean formation at a pressure sufficient to create or enhance a fracture therein; providing an ortho ester breaker; contacting the surfactant gel with the ortho ester breaker; allowing the breaker to hydrolyze to produce an acid and an alcohol; and allowing the acid and/or the alcohol to interact with the surfactant gel so as to reduce the first viscosity of the surfactant gel to a second viscosity. Other methods are provided that include a method comprising: providing a surfactant gel residue having a first viscosity; providing an ortho ester breaker; contacting the surfactant gel residue with the ortho ester breaker; allowing the ortho ester breaker to hydrolyze to produce an acid and an alcohol; and allowing the acid and/or the alcohol to interact with the surfactant gel residue so as to reduce the first viscosity of the surfactant gel residue to a second viscosity.