Study of Permeability Variation with Confining Pressure in Micro-fracture and Low-permeability Rock

The development of low-permeability reservoir is becoming increasingly important. However, its strong diagenesis, fine and close lithology and general development of micro-fracture make permeability, the key symptomatical parameter has strong stress sensitive. In order to get the quantitative relation between permeability and confined pressure in micro-fracture and low-permeability rock, a theoretical relation was attained based on theoretical research and some hypothesis. With its guidance, an experimental study was carried out on three low-permeability cores with natural micro-fracture from certain oil field. Through analyzing the experimental data and matching work, a relation curve was acquired from the experiment by which the undetermined coefficient of the theoretical relation can be obtained, and then the quantitative relation between permeability and confined pressure in the micro-fracture and low-permeability rocks are acquired ultimately.