AN EFFICIENT COMPUTATIONAL MODEL FOR CO2 FLOW IN POROUS MEDIA

This paper presents an efficient computational model for the simulation of fully coupled two-phase flow in a deformed partially saturated formation. Focus is placed on modeling the flow of a CO2 plume in a porous medium. The numerical procedure is based on coupling between the Level-set method (LS) and the extended finite element method (XFEM). The level set is employed to define the location of the front between injected CO2 and existing formation water. A streamline upwind Petrov-Galerkin method is utilized to stabilize the possible occurrence of spurious oscillations in the advection of the CO2 front. The XFEM is employed to model the gradient in the degree of saturation at the front. This is done by decomposing the saturation field into a continuous part and a discontinuous part. The latter is enhanced by the use of a local enrichment function which is calculated on the basis of the Level-set function. Numerical implementation of the method is discussed and numerical examples are given.