Patent ID: 8881820

Claim:
A method comprising: providing a treatment fluid comprising an aqueous base fluid and at least one entangled equilibrium polymer network wherein the entangled equilibrium polymer network comprises a viscoelastic surfactant and network forming material; wherein the network forming material is a hydrophobically modified polymer having a backbone selected from the group consisting of a monomer or polymer that comprises: a vinylpyrrolidone, a vinylpyridine, a polyvinylpyrrolidone, a polyvinylpyridine, a polybutylene succinate, a polybutylene succinate-co-adipate, a polyhydroxybutyrate-valerate, a polyhydroxybutyrate-covalerate, a polycaprolactone, a polyester amide, a sulfonated polyethylene terephthalate, a poly(ε-caprolactone), a poly(phosphazene), any copolymer thereof, any homopolymer thereof, any terpolymer thereof, and any combination thereof; wherein the viscosity of the treatment fluid at zero shear is higher than the viscosity at zero shear of a fluid comprising the network forming material alone and, placing the treatment fluid in a subterranean formation.