An element-based finite-volume method approach for heterogeneous and anisotropic compositional reservoir simulation

An element-based finite-volume approach in conjunction with unstructured grids for heterogeneous and anisotropic compositional simulation is presented. This approach adds flexibility to map complex features of the reservoir such as irregular boundaries, discrete fractures, faults, inclined and distorted wells. The mesh, for two dimensional domains, can be built of triangles, quadrilaterals or a mix of these elements. According to the number of vertex, each element is divided into sub-elements and then mass balance equations for each component are integrated along each interface of these sub-elements. The finite-volume conservation equations are assembled from the contribution of all the elements that share a vertex creating a cell vertex approach. The results for several compositional reservoir simulation case studies are presented to demonstrate the application of the method.