Abstract: The anisotropy model with equivalent/continuous medium and the single-well percolation model considering starting pressure gradient in fractured low-permeability reservoirs are developed by means of the parallel-plane and tensor theories. The effects of natural fractures characterization parameters on the reservoir permeability and pressure distribution are studied by these models. The results show that fracture aperture and density have big effects on average reservoir permeability and anisotropy; the pressure distribution and scope are related to the fracture azimuth; the flow interferences exist between the parallel fracture plane direction and the vertical fracture plane direction. The better the fractures development is, the shorter the pressure affect in the vertical direction. Clear understanding of fracture azimuth and the appropriate well patterns and/or well spaces are the key to enhance the conformance or development efficiency of fractured low-permeability reservoirs.

Key words: fracture, low permeability oil-gas reservoir, percolation, model