Patent ID: 7290614

Claim:
A method of fracturing a subterranean formation, comprising the steps of: a) forming a foamed fracturing fluid comprising: i) water; ii) a surfactant comprising a tertiary alkyl amine ethoxylate generally represented by the following formula: wherein R is an alkyl group or groups, X is about 2 to about 15, and Y is about 2 to about 15; iii) a gelling agent; and iv) a gas; b) introducing the foamed fracturing fluid into a subterranean formation at a pressure sufficient to create a fracture in the subterranean formation; and c) introducing an acid into the subterranean formation; wherein the step of forming a foamed fracturing fluid further comprises the step of forming a foamed fracturing fluid further comprising delayed release acid; and wherein the step of introducing an acid into the subterranean formation comprises the step of introducing the foamed fracturing fluid having the delayed release acid therein into the subterranean formation; and wherein the delayed release acid comprises a chelated material selected from the group consisting of triethyl citrate, dimethyl glutarate, dimethyl succinate, dimethyl adipate, dibasic esters, and any mixtures in any proportion thereof.