Patent ID: 7998908

Claim:
A method for removing preexisting filtercake from a portion of subterranean formation penetrated by a wellbore, the method comprising: providing water-degradable particles formed from a solid polymeric acid precursor material that is capable of degrading to acid for reacting with materials of the filtercake; forming a slurry of the particles with a carrier fluid wherein the carrier fluid comprises water; brine; water based guar; modified guar gel crosslinked with borate and/or organometallic compounds; water viscosified with polymers of HEC, starch, xanthan, and/or scleroglucan; emulsions; cross-linked, energized fluids; and/or water comprising a friction reducer; introducing the slurry of particles into the wellbore; and allowing the water-degradable particles to degrade to form acid, whereby the formed acid facilitates decomposition of preexisting filtercake materials, wherein the filtercake materials have a permeability of less than about 25 millidarcy.