Dilation behavior and acoustic emission response to water/CO2 injection-induced shear fracturing in coal seams

The low permeability of coal seams significantly restrains the efficient extraction of coal-seam methane. Hydroshearing treatment is suitable for enhancing the permeability of coal seams because of their low mechanical strength and unique fracture–matrix structure. The shear dilation behavior associated with the increase in the void volume in porous media is critical for the evaluation of the permeability enhancement during hydroshearing. In...