METHODS OF USING VISCOELASTIC SURFACTANT GELLED FLUIDS TO PRE-SATURATE UNDERGROUND FORMATIONS

摘要

Viscoelastic surfactant (VES) based fluid systems are effective to pre-saturate high permeability subterranean formations prior to a treatment operation that would undesirably suffer from high fluid leakoff. The fluid systems may include brine, a viscosity enhancer, as well as the VES, and a high temperature stabilizer. The stabilizer may be an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxide, alkali metal hydroxide, Al2O3, and mixtures thereof. The viscosity enhancer may include pyroelectric particles, piezoelectric particles, and mixtures thereof. The fluid system is easy to pump into the formation, and after initial pumping, the fluid system will soak into and occupy or "pre-saturate" the pores of the formation prior to pumping of a second treating fluid for fracturing, gravel packing, frac-packing, and the like. The methods are practiced in the absence of acids typically used in acidizing operations, such as hydrochloric acid and hydrofluoric acid.