为了解决坦家冲煤矿2264-1N-S采煤工作面回风巷瓦斯浓度频繁超限问题,提高本煤层钻孔瓦斯抽采率,降低煤与瓦斯突出危险性,提出采用水力压裂增透技术提高煤层透气性。通过对压裂孔周围煤体环向拉应力进行分析,结合环向最大拉应力理论,计算得到煤体裂纹起裂临界水压为15.7 MPa。采用研制出的水力压裂设备进行现场试验后表明:单孔瓦斯抽采流量及抽采浓度均有明显提高,且煤层瓦斯流量衰减系数较低。

In order to solve the gas concentration frequently exceeds the limit in the return airway of the 2264-1N-S working face of TanJiaChong coal mine,the hyd raulic fracture permeability improvement technology was proposed to improve the gas drainage rate,aiming at reducing the risk of coal and gas outbursing and increasin g the permeability.Based on the analysis of the hoop stress around the hole and the maximum tensile stress theory,the critical water pressure of crack initiation was 15. 7 MPa through calculation.When the site test was done by using the developed hydraulic fracture equipment,the results showed that the gas extraction flowrate and con centration of the single bore were significantly improved and the attenuation coefficient of gas flowrate was low.

国家自然科学基金资助项目(51074168)；