Viscoelastic Surfactant Fluids and Related Methods of Use

A method of fracturing a subterranean formation comprising the step of pumping a viscoelastic fluid through a wellbore and into a subterranean formation at a pressure sufficient to fracture the formation, wherein said viscoelastic fluid comprises:

• a) an aqueous medium;
• b) a zwitterionic surfactant represented by the formula (I):
• or the formula (II):
• wherein R1 represents a hydrophobic moiety of alkyl, alkylarylalkyl, alkoxyalkyl, alkylaminoalkyl and alkylamidoalkyl, wherein alkyl represents a group that contains from about 16 to about 22 carbon atoms, which may be branched or straight chained and which may be saturated or unsaturated, and wherein said alkylene groups have from about 1 to about 6 carbon atoms;
• R2 and R3 are independently aliphatic chains having from about 1 to about 30 carbon atoms, and R4 is a hydrocarbyl radical with a chain length of about 1 to about 4;
• c) a member selected from the group consisting of organic acids, organic acid salts, inorganic salts, and combinations of one or more organic acids or organic acid salts with one or more inorganic salts;
• and
• d) an additive selected from the group consisting of corrosion inhibitors and fluid-loss additives and mixtures thereof.

A method of fracturing a subterranean formation comprising the step of pumping a viscoelastic fluid through a wellbore and into a subterranean formation at a pressure sufficient to fracture the formation, wherein said viscoelastic fluid comprises:

• a) an aqueous medium;
• b) a surfactant selected from the group consisting of amphoteric surfactants, zwitterionic surfactants, and mixtures thereof;
• c) an alcohol selected from medium to long chain alcohols;
• and
• d) an additive selected from the group consisting of corrosion inhibitors and fluid-loss additives and mixtures thereof.