"Field trials of nitrogen injection enhanced gas drainage in hard-to-dr" by Jia Lin, Ting Ren et al.
Three stages of nitrogen (N2) injection enhanced gas drainage through underground in-seam boreholes were carried out in a coal mine located in the southern Sydney basin. Due to the high CO2 content and low permeability, hard-to-drain coals were encountered during the excavation process in this coal mine. Two parallel in-seam boreholes (the length of 36 m, the diameter of 96 mm and the borehole space of 5 m) were drilled on the rib of the gateroad. A total of ten-cylinder packs of nitrogen (approximately 1500 m3) were injected into the coal seam. Different nitrogen injection pressures (150 KPa,...