A parallel FE-FV scheme to solve fluid flow in complex geologic media

Field data-based simulations of geologic systems require much computational time because of their mathematical complexity and the often desired large scales in space and time. To conduct accurate simulations in an acceptable time period, methods to reduce runtime are required. A parallelization approach is attractive because fast multi-processor Clusters are nowadays readily available. Here we report on our recent efforts to parallelize Our multiphysics code CSMP + + (Complex System Modelling Platform). In particular, we describe a parallel finite element-finite Volume method for multi-phase fluid flow in heterogeneous porous media. We take a domain partitioning approach where the finite element mesh is partitioned into sub-domains, assigning each of them to a single processor. For each sub-domain a local finite volume mesh is constructed. We can now solve advection-dispersion type equations taking an operator splitting approach: Pressure diffusion is calculated with an implicit finite element method and advection with an implicit or explicit finite volume scheme. We have tested the accuracy, robustness and computational speedup of our new parallel scheme on a Linux cluster by means of three geologic applications. All tests give excellent computational speedup with increasing number of up to 32 processors. These results broaden the range of possible simulations in terms of spatial and temporal scale and resolution as well as numerical accuracy up to two orders of magnitude. (c) 2008 Elsevier Ltd. All rights reserved.