Preparation of a novel forpolymer as fluid loss additive for high temperature oil well cementing

A novel fluid loss additive (FLA) was synthesized using 2-acrylamido-2-methyl-propane sulphonic acid, acrylic acid, N,N-dimethyl acrylamide and N-vinyl-2-pyrrolidone by aqueous solution polymerization. TGA spectrum indicated that the decomposition temperature of FLA was higher than 330°C. The fluid loss testing showed that the FLA had an outstanding property of reducing fluid loss at 203°C in salt water cement slurry and the amount of fluid loss was controlled about 100 mL when FLA dosage was 1.0%. Cement slurry with 0.1–1.5% FLA kept stable thickening time. A better performance of FLA was found in fresh water cement slurry than in salt water cement slurry.