Design on Borehole Drilling Site for Mine Gas Drainage Based on Gas Migration Features in Goaf

In order to conduct a design on a borehole drilling site for the mine gas drainage from the goaf of the high gassy coal mining face and to effectively contr ol the gas at the top corner of the goaf and the top corner of the coal mining face,the numerical simulation was applied to study the overburden strata structures and the fracturing development law of the coal mining face.According to the simulation results,the lab experiments were applied to analyze the gas migration features of the gas drainage boreholes in different location of the goaf. The borehole terminal location measured had a distance about 30 m in the roof above seam.When the borehole term inal location had a horizontal distance of 1020 m to the air returning gateway,the gas drainage effect would be best.The borehole terminal height would be different base d on the overburden strata structure above the coal mining face.The borehole height near the air returning gateway should be controlled above the regular falling zone. The borehole near the middle of the coal mining face should be set in the cracking zone.