Abstract: A targeted heterogeneous medium in the form of an underground layered formation is gridded into a layered structured grid or a layered semi-unstructured grid. The structured grid can be of the irregular corner-point-geometry grid type or the simple Cartesian grid type. The semi-unstructured grid is areally unstructured, formed by arbitrarily connected control-volumes derived from the dual grid of a suitable triangulation; but the connectivity pattern does not change from layer to layer. Problems with determining fluid movement and other state changes in the formation are solved by exploiting the layered structure of the medium. The techniques are particularly suited for large-scale simulation by parallel processing on a supercomputer with multiple central processing units (CPU's).

Abstract: A fully-parallelized, highly-efficient compositional implicit hydrocarbon reservoir simulator is provided. The simulator is capable of solving giant reservoir models, of the type frequently encountered in the Middle East and elsewhere in the world, with fast turnaround time. The simulator may be implemented in a variety of computer platforms ranging from shared-memory and distributed-memory supercomputers to commercial and self-made clusters of personal computers. The performance capabilities enable analysis of reservoir models in full detail, using both fine geological characterization and detailed individual definition of the hydrocarbon components present in the reservoir fluids.