Patent ID: 8008236

Claim:
A method comprising: providing a surfactant gel having a first viscosity that comprises an aqueous base fluid and a surfactant wherein the surfactant gel comprises at least one metal ion having at least two oxidation states wherein at least one of the oxidation states interferes with the ability of the surfactant to form viscosifying micelles; wherein the surfactant is selected from a group consisting of a methyl ester sulfonate; a sulfosuccinate; a taurate; an amine oxide; an ethoxylated fatty amine; a quaternary ammonium compound; an erucyl methyl bis(2-hydroxyethyl) ammonium chloride; and a combination thereof; providing an ortho ester breaker; contacting the surfactant gel with the ortho ester breaker; allowing the ortho ester breaker to hydrolyze to produce an acid and an alcohol; and allowing the alcohol to interact with the surfactant gel so as to reduce the first viscosity of the surfactant gel to a second viscosity.