Dissipative particle dynamics simulation and study on solution properties of polymer surfactants

To enhance oil recovery of high-salinity and heterogeneous heavy oil reservoirs, dissipative particle dynamics (DPD) simulations have been performed to determine the properties of KL-6 polymer surfactant solution, molecular structure and viscosity-enhancement mechanism of KL-6 have been analyzed, and comparison has been made with partially hydrolyzed polyacrylamide (HPAM). Based on DPD simulation, conditions of PAM, HPAM, KL-6 in water have been determined to highlight the impact of molecular chain structures on properties of polymer molecules, viscosity-enhancement capacities of HPAM and KL-6 solutions at different concentrations have been analyzed to compare microscopic structures, viscosity-enhancement capacities, surface activity and salinity-resistance of these HPAM and KL-6 polymer solutions. Research results show that KL-6 has both intermolecular association and surface activity with a critical association concentration of 0.6 g/L; at an association concentration higher than the critical, KL-6 solution has viscosity significantly higher than that of HPAM; at the same concentration, KL-6solution has surface activity much more than that of HPAM; with molecular chains to form 3D network structures in salt solution, KL-6 displays outstanding salinity resistance. Relevant research results may provide theoretical basis for development and application of desirable polymer surfactants.