Preparation of VCAP/AMPS/DMDAAC/AM Quaternary Copolymer Filtrate Reducer for Drilling Fluids

Abstract

It is difficult for existing filtrate reducer to meet oilfield application requirements. Based on the molecular structure design principle of temperature-resistant vinyl copolymer, a quaternary copolymer filtrate reducer has been developed with VCAP, AMPS, DMDAAC and AM as monomers through water solution copolymerization using redox initiation system. The optimum synthesis conditions were as follows: the mole ratio of monomer was VCAP/AMPS/DMDAAC/AM=1:1:1:9, reaction temperature was 70°C, reaction time was 6 h, initiator mass ratio was 0.2% and total monomer mass ratio was 20%. The filtration loss of base slurry with 1wt% optimum synthetic product after aging at 150 °C for 16 h was 5.2 mL.