EXPERIMENTAL STUDY ON PERMEABILITY VARIATION WITH CONFINING PRESSURE IN MICRO-FRACTURE AND LOW-PERMEABILITY ROCK

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