低透气性煤层水力压裂增透数值模拟研究  

Study on numerical simulation of hydraulic fracturing permeability-enhancement for low-permeability coal seam

作　　者：何福胜 毕建乙 王海东 He Fusheng;Bi Jianyi;Wang Haidong(Xiegou Coal Mine of Shanxi Xishan Jinxing Energy Co.,Ltd.,Lvliang,Shanxi 033602,China;Safety Engineering College,North China Institute of Science and Technology,Sanhe,Hebei 065201,China)

机构地区：[1]山西西山晋兴能源有限责任公司斜沟煤矿,山西省吕梁市033602 [2]华北科技学院安全工程学院,河北省三河市065201

出　　处：《中国煤炭》2018年第10期136-142,173,共8页China Coal

基　　金：国家自然科学基金资助项目(50704024)

摘　　要：针对高瓦斯低透气性煤层抽采率低下、钻孔工程量大及抽采周期长的难题,提出水力压裂卸压增透技术。借助RFPA2D-Flow软件模拟分析了压裂时压裂孔附近煤体从发生破裂、裂隙裂纹的生成演化、扩展延伸到最终贯通的完整过程,得到钻孔附近煤体的裂隙裂纹演化规律。通过在斜沟煤矿18205材料巷实施水力压裂现场试验,发现当水压升高至16MPa时有效影响半径为7m,试验结果与模拟结果基本一致;水力压裂影响范围内煤层的透气性系数提升14倍,瓦斯抽采浓度提高了4.43倍,抽采纯量提升了9.62倍,抽采效果显著提高。In order to solve the problems of low drainage rate,high drilling volume and long drainage cycle in high-gas and low-permeability coal seams,hydraulic fracturing pressure-relief and permeability-enhancement technology was proposed.The RFPA2 D-Flow software was used to simulate and analyze the complete process of coal fracture and fissure generation,revolution,extension and cut-through around borehole,and the revolution law of cracks and fissures in coal body around borehole was obtained.Through hydraulic fracturing site test in 18205 roadway in Xiegou Coal Mine,it found that when the water pressure rose to 16 MPa,the effective influencing radius was 7 m,the test results was basically the same with the simulation results;the permeability coefficient of the coal seam within the influence range of hydraulic fracturing was increased by 14 times,and the gas drainage concentration was increased by 4.43 times,and the drainage quantity was increased by 9.62 times.The effect of gas drainage was significantly improved.

关 键 词：低透气性 裂隙裂纹 水力压裂 卸压增透 剪应力 数值模拟 

分 类 号：TD713.34[矿业工程—矿井通风与安全]