摘要
为了解决低渗透煤层抽采效果差、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RFPA^(2D)-Flow软件模拟了压裂过程中压裂孔附近煤层从发生破裂、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:伴随注水压力的持续升高,裂隙裂纹范围及最大剪应力也在增加,且随着压裂孔附近裂隙裂纹的延伸扩展,最大剪应力升高的同时在不断靠近控制孔;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16 MPa时有效影响半径为7 m,试验结果与模拟结果基本一致;压裂影响区域钻孔抽采浓度提高3. 43倍,抽采纯量增大8. 65倍,煤层透气性系数升高13. 4倍,抽采效果得到明显改善。
In order to solve the problems of poor extraction effect,large drilling capacity and long extraction period in low permeability coal seams,the technique of hydraulic fracturing decompression is proposed.Using RFPA 2D -Flow software to simulate the complete process of coal seam near the fracturing hole from rupture,crack generation evolution,extension to final penetration during fracturing process,the law of crack evolution of coal body near drilling is obtained:accompanied by continuous increase of water injection pressure.The crack range and the maximum shear stress are also increasing,and the maximum shear stress increases as the crack extends near the fracturing hole.By carrying out the hydraulic fracturing field test in the 18205 material lane of Xiegou Coal Mine,it is found that when the water pressure rises to 16 MPa,the effective influence radius is 7 m,and the test results are basically consistent with the simulation results.The drilling and extraction concentration in the area affected by fracturing increased by 3.43 times,the purity of extraction increased by 8.65 times,and the permeability coefficient of coal seams increased by 13.4 times,and the extraction effect was significantly improved.
作者
李新明
梁忠秋
LI Xin-ming;LIANG Zhong-qiu(Xiegou Coal Mine of Shanxi Xishan Jinxing Energy Co., Ltd.,L liang033602,China;Shenyang Research Institute Co., Ltd., of China Coal Industry Group,Fushun 113122,China;State Key Laboratory of Coal Mine Safety Technology,Fushun113122,China)
出处
《煤》
2019年第4期1-4,7,共5页
Coal
基金
国家自然科学基金资助项目(51204088)
国家重大科技产业工程计划(2016ZX05067004-003)
关键词
水力压裂
卸压增透
剪应力
有效影响半径
hydraulic fracturing
unload and increase penetration
shearstress
effective impact radius
