  Polymer flooding is a mature enhanced oil recovery technique that has been
successfully applied in many field projects. By injecting polymer into a
reservoir, the viscosity of water is increased, and the efficiency of water
flooding is improved. As a result, more oil can be recovered. This paper
presents numerical simulations of a polymer flooding process using parallel
computers, where the numerical modeling of polymer retention, inaccessible pore
volumes, a permeability reduction and polymer absorption are considered.
Darcy's law is employed to model the behavoir of a fluid in porous media, and
the upstream finite difference (volume) method is applied to discretize the
mass conservation equations. Numerical methods, including discretization
schemes, linear solver methods, nonlinearization methods and parallel
techniques are introduced. Numerical experiments show that, on one hand,
computed results match those from the commercial simulator,
Schlumberger-Eclipse, which is widely applied by the petroleum industry, and,
on the other hand, our simulator has excellent scalability, which is
demonstrated by field applications with up to 27 million grid blocks using up
to 2048 CPU cores.
