Copolymer Grafted Nano Silica Particles for Enhanced Oil Recovery from Low-Permeability Reservoirs

Because of their small particle size, excellent stability, high temperature tolerance, and salt tolerance, polymer nanoparticles are attracting a lot of attention in low-permeability reservoirs. In this study, SiO2, acrylamide (AM), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) were used to synthesize novel copolymer-grafted nano-silica particles (HPGN). HPGN’s overall performance in low-permeability reservoirs was evaluated. The results demonstrate that the viscosity of a 2000 mg/L HPGN solution at 50 °C is 75.8 mPa·s, with high stability under high temperature, high salt, and shear conditions. More notably, the displacement experiment proved that under the condition of 18450 mg/L, a 2000 mg/L HPGN solution enhanced the recovery rate by 21.89%. This research indicates that HPGN has great applicability potential in low-permeability reservoirs with high temperatures and salinities.