Patent ID: 7387986
Filing Date: 2008-06-17
Classification: C09K,C11D

Abstract:
1. An oilfield treatment method comprising: a. viscosifying a fluid with a viscoelastic surfactant system having an entangled micelle structure selected from at least one of zwitterionic, amphoteric, and cationic surfactants and mixtures thereof, said entangled micelle structure being disrupted by application of shear and having a shear recovery time for said micelle structure to reheal wherein the viscosified fluid has a rheology comprising a viscosity recovery time at relatively low shear conditions following a reduced viscosity from high shear conditions; b. adding to the fluid a rheology enhancer in the fluid in a concentration sufficient to shorten the viscosity recovery time of the viscoelastic recovery system, said rheology enhancer being a polymer comprising at least one portion selected from partially hydrolyzed polyvinyl esters; and c. injecting said fluid down a well.