Research on Permeability of Coal Samples with and without The Effect of Supercritical CO_2

摘要

To improve the low-permeability coal seam gas drainage and gas prevention and to seek the methods to improve the permeability of low-permeability coal, the experimental study on supercritical CO_2 on coal was conducted in the laboratory conditions, and the experiment on pseudo-triaxial permeability testing for coal samples, with and without supercritical CO_2, was conducted. The results show that due to the effect of supercritical CO_2 on coal like physi-chemistry, the porosity of coal was changed, which markedly varied the permeability of coal samples before and after the effect of supercritical CO_2; the permeability of the experimented coal samples was significantly higher than before, and average permeability increased by nearly an order of magnitude under the same volume-stress.