Grid direction selection and grid size design are two important elements that need to be considered in the grid direction design in reservoir numerical simulation. Reservoir engineers normally utilize geological data (such as the distribution of fractures, low permeability zones,
faults and major stress) and simulation experiences to design the grid direction of simulation model qualitatively. The research of the paper indicates that the key to determine the grid direction is to determine the principal permeability direction. Under the circumstances of few static materials, a new grid direction determination method has been developed by using field data (well location map and inter-well permeability) on the bases of Darcy’s law and tensor analysis theory. The grid direction of WZ11-7 Oilfield simulation model has been determined using four production wells and two production zones (L1 and L3) in WZ11-7-2 well group, the results are in conformity with the geological
studied major stress. Therefore, this method can give insights into the numerical simulation study.