Method of improved reservoir simulation of fingering systems

The present disclosure includes the use of grids composed solely or in part of a set of contiguous cells having six or more principal flow directions within a single layer is disclosed for use in numerical simulation. The grids are particularly well-adapted for use in modeling flow in hydrocarbon-bearing reservoirs where fingering or channeling is experienced. Methods of constructing a bisected periodic grid and a substantially constant width radial grid in connection with the present disclosure are also provided. The problem of grid orientation effects is lessened by providing grids with an increased number of principal flow directions, typically six or more. The improved grids may be used in many preexisting simulators.