Differences in coal bed methane occurrence for different regions of igneous erosion in the Haizi coal mine, Huaibei coalfield, China

Abstract

Igneous erosion would change the coal bed methane (CBM) occurrence in coal. Based on the different occurrences of magma rock at the II101 and II102 mining areas in the Haizi coal mine of the Huaibei coalfield in China, coal bed methane occurrence in different regions of igneous erosion was studied by collecting and categorizing CBM parameters during the establishment and mining of the II101 and II102 mining areas. The CBM pressure gradient, CBM content, and CBM emission during mining the workface for the II102 mining area with more stable and thicker magmatic rock were larger than those of the II101 mining area. The CBM pressure gradients for the II101 and II102 mining areas were 0.02397 MPa/m and 0.03736 MPa/m, respectively. With increasing depth, the CBM contents of both the II101 mining area and the II102 mining area increased and the CBM content of the II102 mining area was greater than that of the II101 mining area. The absolute CBM emission (AE) gradient and the relative CBM emission (RE) gradients for the II101 mining area were 0.012 m3/min/m and 0.023 m3/t/m, respectively. Additionally, the AE gradient and the RE gradient for the II102 mining area were 0.031 m3/min/m and 0.055 m3/t/m, respectively. Partition management for different regions of igneous erosion should be used.