Flow Behavior of Viscoelastic Polymer Solution in Porous Media

Polymer solution flowing in porous media is difficult to characterize and simulate due to the effect caused by the rheological behavior and physicochemical reaction. In this study, a mathematical model of viscoelastic polymer flooding for enhancing oil recovery is presented. The model combines a viscoelastic constitutive model, together with a modified permeability model and a new relative permeability model. The effect of the rheology of polymer solution in porous media, the parameters of pore throat, the residual resistance factor, and the residual oil saturation reduction related to polymer's viscoelasticity have all been taken into account in this new model. We use the implicit operator splitting method to handle the concentration equations, the conjugate gradient method to solve the implicit pressure equations, and the third-order total variation diminishing method to handle the upwind scheme for explicit coefficients. The model is verified with the experimental data. In addition, the numerical model is used to analyze the displacement characteristics of polymer solution flow in porous media influenced by the rheological behavior and porous characters. Also, a typical case of polymer flooding simulated by this new model is demonstrated.