Synthesis and performance evaluation of an amphiphilic polymer viscosity reducer for heavy oil

A series of amphiphilic polymer viscosity reducers PBP were synthesized using bromoalkanes, polyethyleneimine, acrylamide and 2-acrylanmido-2-methylpropanesulfonic acid as raw materials by free radical polymerization, and characterized by FTIR, 1HNMR and GPC. The effects of PBP-12 (12 is the carbon atom number of bromoalkane) on emulsification, viscosity reduction and oil displacement of heavy oil were investigated by using microscope, video spinning drop tensiometer and rheometer. When the mass fraction of PBP-12 was 1.00% and the oil-water mass ratio was 7:3, the heavy oil with viscosity of 4753 mPa•s in Chunfeng oilfield could be reduced to 85 mPa•s, and the viscosity reduction rate was 98.21%. Meanwhile, the oil-water interfacial tension was reduced from 11.59 mN/m to 0.06 mN/m. The viscosity reduction rate was 93.75% after aging at 110 ℃ for 24 hours. The mineralization degree was 1.45×105 mg/ L, the viscosity reduction rate was 93.50%. At 50 ℃ and 4.84×104 mg/L, the viscosity of PBP-12 solution with mass fraction of 0.50% was 56 mPa•s, higher than of commercial partially hydrolyzed polyacrylamide solution (32 mPa•s). The viscosity reducer flooding could increase the oil recovery by 37.45% on the basis of water flooding. The results showed that PBP-12 had good temperature and salt resistance and exhibited better aqueous thickening capability under high mineralization condition, and its solution could improve the recovery by reducing the heavy oil viscosity and expanding the sweep volume. © 2022, Editorial Office of FINE CHEMICALS. All right reserved.