Patent ID: 7677311

Claim:
A method of treating a subterranean formation penetrated by a wellbore comprising a formation surface comprising a) injecting into the formation through the formation surface a fluid comprising a viscosifier and a solid additive comprising particles sufficiently small to pass into the formation pores, said solid additive comprising a material degradable in the formation, and b) allowing said additive to degrade into a material soluble in a fluid in the pores after the injection; wherein the particles comprise a material selected from the group consisting of waxes, polycarbonates, polyacetals, polymelamines, polyvinyl chlorides, polyvinyl acetates, polyvinyl esters, polyacrylates, polymethacrylates, polycarboxylates, and mixtures thereof; and wherein the fluid further comprises a pH control agent present in an amount sufficient to neutralize any acid or base present in the solid material before the injection and any acid or base generated by the solid material during the injection.