Abstract: A method of treating a formation penetrated by a wellbore to reduce fluid loss to the formation is carried out by providing a quantity of water-degradable particles formed from a solid polymeric acid precursor having a number average molecular weight (Mn) of greater than 4000. A slurry of the particles is formed with a carrier fluid, which may be an aqueous fluid. The slurry is introduced into the formation through the wellbore at a pressure below the fracture pressure of the treated formation. A treating fluid is subsequently introduced into the formation through the wellbore. The water-degradable particles degrade by contacting the particles with a free aqueous fluid introduced into the formation through the wellbore. The water-degradable particles may have a particle size of from about 0.25 mm or less. The slurry may contain from about 0.01 kg/L to about 0.15 kg/L of the water degradable particles.