Experimental Study of the Effective Stress Coefficient for Coal Anisotropic Permeability

The effective stress plays an essential role in predicting the permeability of the coal reservoir during coalbed methane (CBM) production. However, the importance of the effective stress coefficient (ESC) for permeability evolution has always been neglected. In this work, a series of permeability measurements were performed on cores of different directions under constant confining pressure (CCP) conditions and constant pore pressure conditions...