| abstract |
A method for removing preexisting filtercake from a portion of a subterranean formation penetarted by a wellbore is carried out by providing water-degradable particles formed from a solid polymeric acid precursor material that is capable of a degrading to acid for reacting with materials of the filtercake. A slurry is formed from the particles with a carrier fluid. The slurry of particles is introduced into the formation through the wellbore and allowed to degrade to form acid, whereby the formed acid facilitates decomposition of preexisting filtercake material. In certain applications, the water-degradable particles may also be used in combination with non-water-degradable particles, which may be used for forming a gravel pack. The water-degradable particles may also be used to reduce fluid loss temporarily to areas of the formation immediately surrounding the wellbore. |