Near-Well Upscaling for Reservoir Simulations

Upscaling of absolute permeability from geological/geostatistical models to reservoir flow simulation models has been discussed for a long time. It has been generally recognized that the main difficulty in upscaling is the dependence of upscaling results on boundary conditions, which lead to a nonunique solution. As a consequence of inaccurate permeability upscaling, well performance prediction might be very different using fine and coarse grid simulations. In this paper, the technique of near-well upscaling, which can improve dramatically coarse grid simulation accuracy for well productivities in heterogeneous media, is presented. The proposed near-well upscaling has been developed for 3D complex wells on both Cartesian and corner-point geometry (CPG) gridblocks. Equivalent results on well productivity are obtained between coarse grid and fine grid simulations.