三软煤层水力冲孔布孔参数确定及优化∗

摘要

In order to increase the effect of hydraulic flushing to eliminate gas outburst in the"three soft"coal seam,the effective radius of hydraulic flushing was determined using the COM-SOL software simulation,the parameters of hole arrangement were optimized and tested by com-bing the field experiments and application��The results show that the parameters of hole arrange-ment is determined by the analysis of the range of pressure relief and the radius of gas drainage, when the flushed coal quantity is 0��5 t/m,0��75 t/m,1��0 t/m respectively,the range of pressure relief is 6��7 m,8��9 m,1 1��2 m respectively,and the radius of gas drainage is 3��2 m,4��5 m,5��3 m respectively;According to the optimal results of field experiments,the pitch of holes to hy-draulic flushing is 9 m,and the gas concentration and the gas flow rate to area effect testing in-creases from 25%,0��08 m3/min before hydraulic flushing to 85%,0��35 m3/min after hydraulic flushing respectively,which shows the parameter of hole arrangement is reasonable and reliable.%为提高“三软”煤层水力冲孔瓦斯消突效果,采用 COMSOL软件进行模拟以确定冲孔有效半径,结合现场试验及应用对布孔参数进行优化与检验。结果表明,冲煤量为0��5t/m、0��75t/m、1��0t/m时,卸压范围分别为6��7m、8��9m、11��2m,瓦斯抽采半径为3��2m、4��5m、5��3m；根据糯东煤矿现场试验优化确定水力冲孔孔间距为9m,区域效果检验瓦斯抽采浓度及流量由冲孔前的25％,0��08 m3/min 升至冲孔后85％,0��35 m3/min,确定布孔参数合理可靠。