Modeling nonuniform mixing of polymer in Enhanced Oil Recovery by polymer flooding

It is customary to take polymer uniformly mixed with water when modeling flow of polysolution (polymer mixed with water) in displacing immiscible oil phase during enhanced oil recovery by polymer flooding. We put forward a proposal to account for inhomogeneous mixing by introducing a mixing parameter $omega$ that is used to find the effective viscosity of the aqueous phase. When $omega=1$, water and polymer are fully mixed, while the polymer solution is completely segregated from pure water if $omega=0$. Simulations of polymer-surfactant flooding with and without shear thinning polymer using our in-house code are performed. The code is based on a hybrid numerical method which uses a discontinuous finite element method and modified method of characteristics. Numerical results for several values of the parameter $omega$ in the range $0 le omega le 1$ will be presented and analyzed to evaluate the effect of nonuniform mixing on flow and oil recovery.

[1] Prabir Daripa and Sourav Dutta, “Modeling and simulation of surfactant–polymer flooding using a new hybrid method”, J. Cmp. Phys., volume 335, pp. 249-282 (2017).