STUDY ON SEEPAGE CHARACTERISTICS AND MODEL OF ORTHOTROPIC ANISOTROPY COAL

The extraction of coalbed methane can ensure the safe production of coal mines and the efficient use of resources. According to the anisotropy of coal seam, CT spiral scanning and triaxial gas seepage tests are carried out, the seepage characteristics of orthotropic coal are analyzed, and a coal permeability model considering orthotropic structure is proposed. Results show that: The permeability of parallel bedding direction changes obviously with axial pressure. The confining pressure is 5 MPa, the permeability in the parallel bedding direction is about 1.6 times that of the vertical bedding, and the confining pressure is 13 MPa, the permeability in the parallel bedding direction is about 1.01 times that of the vertical bedding. The coal permeability model with anisotropic structure is verified by the experiment data in both parallel and vertical bedding directions, and shows great applicability. Research results provide references for the efficient development of coalbed methane.