Efficient Drainage Technology of Released Gas from Adjacent Layer at Working Face of Y Ventilation

In order to reduce the waste of coal resources and actively respond gas management dilemma at working face caused by restrictions about "U + L" ventilation from national or local mine monitoring department, the high water filling gob-side entry technology was applied in goaf of experimental working face for special conditions of contiguous coal seam group in Xingwu Coal Mine, "U + L" ventilation of working face was converted to Y type ventilation, the released gas of adjacent layer was extracted by oblique borehole. The results indicated that drainage rate was increased 10% to 47% by oblique borehole, and the need of gas drainage could be satisfied by this method after Y ventilation.