Simulation of the multiphase molecular effect of polymer flooding oil

Abstract

Polymers are widely used in the tertiary oil recovery process due to their high stability, light weight and low cost. However, the macroscopic experimental research of polymers is limited by its own hypothetical conditions and cannot obtain good simulation results, which is not enough to reveal the mechanism of polymer flooding. In this paper, combing chemical, computer science and molecular dynamics methods, using non-ionic polyacrylamide, a polymer flooding model is established to simulate the movement of multiphase molecules in the process of polymer flooding from the microscopic level.Studying the diffusion, adsorption and aggregation of multiphase molecules, it was found that the diffusion rate of water molecules and NPAM molecules decreases with the growth of NPAM molecular chains. When NPAM molecules reach the critical concentration of aggregation, the interaction force between NPAM and kaolinite reaches saturation. Shearing can disrupt the length of NPAM molecular chains and accelerate the diffusion of NPAM molecules. The phenomenon of local aggregation of NPAM molecular chains in polymer solution systems occurs. revealing the interaction process of multiphase molecules in the process of polymer flooding, quantifying the diffusion laws of three molecules (polymer, oil and water), and enriching the theoretical system of polymer flooding flow.