Study of new filtrate reducer of acrylamide copolymer used for cementing

Aim at the difficulty of separate layer to high auifer bed,fractured and high permeability formation,The copolymer which made from 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and acrylamide (AM) was synthesized, which are root of the chemical character of polyvinyl alcohol (PVA). Examination results in laboratory show that the credible application temperature of the copolymer is 120℃ and the API fluid loss of slurry will less than 50 mL while the dosage of the copolymer in cement in the range of 0.32~0.80 at the temperature ranging from 50 to 90℃. The evidences of field application indicate that this copolymer can be used for primary cementing job that the length of cementing is less than 600 m. It is propitious to isolate the high aquifer formation, shallow natural gas layer and high permeability formation.