马堡煤业高压水力压裂冲孔工业试验分析

Industrial Test Analysis of High Pressure Hydraulic Fracturing Punching in Mabu Mining Industry

为探究马堡煤业水力压裂冲孔增加煤层瓦斯渗透率的适用性,采用RFPA2D-Flow数值模拟软件建立了高压水力压裂冲孔数值模型,分析了不同注水压力条件下裂纹的扩展规律,并以8205运输巷底抽巷为试验对象开展了穿层水力压裂增透工业试验。结果表明:在马堡煤业煤层条件下,注水压力为8 MPa可使煤层产生初始破坏,注水压力为13 MPa可使裂隙快速扩张,注水压力为18 MPa可使煤层裂隙充分达到破坏。工业试验中,采用18 MPa的注水压力可使水力压裂的裂隙影响范围达到1.10~4.45 m,满足煤层的增透性需求。水力压裂钻孔组平均抽采体积分数是无水力压裂钻孔组的3.8倍。

In order to explore the applicability of hydraulic fracturing punching in Mabu Mining Industry to increase coal seam gas permeability,RFPA 2D-Flow numerical simulation software was used to establish a numerical model of high-pressure hydraulic fracturing punching,and the crack propagation law under different water injection pressure conditions was analyzed,and the industrial test of peramination hydraulic fracturing and permeability enhancement was carried out with 8205 transportation trough bottom pumping as the test object.The results show that under the conditions of Mabu mining seam,a water injection pressure of 8 MPa can cause initial damage to the coal seam,a water injection pressure of 13 MPa can make the crack expand rapidly,and a water injection pressure of 18 MPa can fully damage the coal seam fracture.In the industrial test,the water injection pressure of 18 MPa can make the fracture influence range of hydraulic fracturing reach 1.10~4.45 m,which can meet the permeability requirements of coal seam.The average extraction concentration in the hydraulic fracturing drilling group was 3.8 times that of the non-hydraulic fracturing drilling group.