A 3D compositional miscible gas flooding simulator with dispersion using Element-based Finite-Volume method

Physical dispersion is one of the most important key parameters in compositional reservoir simulation. It is a phenomenon of mixing with mass transfer occurring when gradients in composition arise or exist. This process tends to homogenize the composition of the phases. When the dispersion term is included in the material balance equations, we obtain a full tensor structure. However, most of the reservoir simulators neglect such an important physical term. In this work, we investigate the governing partial differential equations for modeling miscible flooding by adding dispersion to the material balance equations. The equations are solved by the Element-based Finite-Volume method (EbFVM) in conjunction with unstructured meshes. Results of several compositional reservoir simulation case studies are presented to demonstrate the application of the method.