A Mixed Dimensional Finite Volume Method For Multiphase Flow In Fractured Porous Media精品.pdfVIP

A mixed-dimensional finite volume method for multiphase flow in fractured porous media 1 2 Volker Reichenberger , Hartmut Jakobs , 1 2 Peter Bastian , Rainer Helmig We present a vertex-centered finite volume method for the fully coupled, fully implicit discretization of two-phase flow in fractured porous media. Frac- tures are discretely modeled as lower dimensional elements. The method works on unstructured, locally refined grids and on parallel computers with distributed memory. An implicit time discretization is employed and the nonlinear systems of equations are solved with a parallel Newton-multigrid method. Results from two-dimensional and three-dimensional simulations are presented. Keywords: Multiphase flow; Numerical reservoir simulation; Fractured reser- voir; Mixed-dimensional Finite Volume Method; Multigrid Methods. 1 Introduction Fractures are present in many subsurface systems and can strongly influence or even domi- nate fluid flow and transport behavior. Because of the importance of fractured systems for secondary recovery techniques, waste disposal safety analysis and remediation techniques they have been investigated since the 1960s (Barenblatt et al., 1960; Warren and Root, 1963) and still receive considerable attention. The difficulties which arise for conceptual and numerical modeling stem from the strongly heterogeneous and anisotropic nature of the fracture-matrix system. For multiphase flow problems the behavior is much more complex than in the case of a single phase, since in the presence of two phases fractures may act as barriers or main flow paths, dependi