We use the IMPES pressure solver to compute the solution to the SPE1 benchmark case which models the injection of gas into an initially undersaturated oil reservoir.
The Implicit Pressure, Explicit Saturation (IMPES) module is an experimental solver for compressible, miscible black-oil type flow and transport. The solver uses a two-point flux approximation scheme and can be used either as a pressure solver or as a combined pressure-saturation solver.
Download
As from the MRST 2012a release, this module is bundled witn MRST Core in the standard release.