Abstract: Low-permeable abnormal high-pressure reservoirs own some characters that elastic energy is abundant, and reservoirs are under-compacted, and rocks are prone to elastoplastic deformation. According to these features, an approximate relationship of final recovery and petrophysical property based on Darcy’s law is achieved; and the concept of permeability variation factor is introduced to analyze the affecting factors on recovery rate. Taking West Wen-13 block for example, exploitation methods of such reservoirs are analyzed and discussed by means of permeability variation factor, combining with pressure sensitive experiment of different fluid permeability, experiments of permeability change in different pressure loading modes, and depressurizing elastic drive and water flooding experiments. The results show that a higher oil recovery can be obtained by maintaining slower depressurizing speed and higher pore pressure.

Key words: permeability, variation factor, fluid medium, loading modes, elastic drive, water flooding