Implementation of a Vertex Centered Method inside an Industrial Reservoir Simulator - Fault Modeling Aspects

Corner point grids and pillar based unstructured grids do not provide an effective workflow for translating earth models into simulation models. It requires grids that allow an accurate representation of the near well flow and preserving geological accuracy and offering flexible resolution control. Hence a 3D unstructured approach is required.

Significant work has been done for generating unstructured grids. Coupling with geomechanics and hydraulic fracture flow for gas shale simulation have given a new impulse for unstructured gridding. Recent methods such as VAG or more mature ones such as MPFA provide a numerical scheme based on multipoint stencil more physical than two point flux methods.

Paper presents the application of three multi-point stencil methods (namely VAG, MPFA-O, MPFA-L) on a faulted full field model. Main issues addressed are the fault discretization using unstructured grid and the benefits compared to the usual structured grid and fault multipliers approach.

Results, accuracy and performance of multipoint scheme methods on unstructured grids are compared with TPFA methods on structured CPG grids and PEBI method on unstructured grids.

Two simulation examples are presented and compare results, accuracy and performance. The first test case is a Y fault model and the second one is a full field faulted model.