Interconnected pore development features of high rank coal based on 3D space characteristics

In order to discuss the pore interconnection features of the high rank coal, based on No.3 anthracite seam at the south part of Qinshui Basin as a study o bject, the 3D digitalized modeling method of the coal reservoir structure was applied to establish the multi grade pore crack network structure model of the seam and topick up the key parameters. In combination with the observation of the scanning electron microscope, the pore crack interconnection relationship and the contribution of the different origin type pore crack to the coal reservoir interconnection were further confirmed. The results showed that the pore throat of the high rank coal was fine a nd small and the high rank coal was mainly with the medium pores with a pore diameter less than 50 nm. the tortuosity of the crack was low, the section was mainly withthe square and regular triangle and the capillary resistance was low. The interconnection of the crack was poor and the medium pore with the pore diameter less than 50 nm would play the main function to the interconnection. The differential shrinking pores were the main nano interconnected pores. The pore development could formt he seepage network structure with a certain network topological property. The pore crack network structure could characterize the pore crack distribution features and t opological relationship and could release the digitalized and visualized characteristics of the coal and rock internal space.