Structure features of high rank coal in parallel bedding and vertical bedding based on low field nuclear magnetic resonance

In order to improve the understanding of the fluid migration and output in the development of the coalbed methane horizontal well, with the high rank coal in the south part of Qinshui Basin as a study object, based on low field nuclear magnetic resonance test, the paper had a discussion on the structure features of the high rank coal reservoir in the parallel bedding and vertical bedding directions and had a further statement on the causes of the coal reservoir structure differences in the parallel bedding and vertical bedding directions. The results showed that the high rank coal in the parallel bedding and vertical bedding directions would have similar pore diameter distribution features. The porosity of the high rank coal in the parallel bedding direction would be lower than in the vertical bedding direction. But the connectivity between the big pores and micro cracks as well as between the medium pore and the big pore with a pore diameter of