Experimental Study on Microscopic Structure and Permeability of Tectonic Soft Coal
To analyze the mining effect to gas permeability of tectonic soft coal seam, we choose typical sample from tectonic soft coal, study the gas permeability and microstructure. The results suggest that tectonic soft coal has been badly destroyed, and its micro fracture pore develops. Confining pressure has a great influence on the permeability of tectonic soft coal. When gas pressure remains constant, with the increase of confining pressure of tectonic soft coal permeability began to decrease very fast. But when decreasing to a certain degree, it changes slowly; when confining pressure remains constant, with the increase of gas pressure, permeability of tectonic soft coal first decreases and then increases. Under the condition of low gas pressure, tectonic soft coal permeability shows a significant Klinkenberg effect.