煤矿井下水力压冲增透强化抽采技术试验研究

1.重庆市能源投资集团科技有限责任公司,重庆 400060; 2.中煤科工集团 重庆研究院,重庆 400037; 3.河南理工大学 能源科学与工程学院,河南 焦作 454003

水力压冲; 增透; 多级裂隙; 强化抽采

Experimental research on enhanced gas extractionapplication with hydraulic fracturing and flushing
XU Tao1,FENG Wen-jun 2,SU Xian-bo3

(1.Chongqing Energy Investment Group Science and Technology Co.,Ltd.,Chongqing 400060,China; 2.Chongqing Research Institute,China Coal Technology & Engineering Group,Chongqing 400037,China; 3.School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China)

hydraulic fracturing and flushing; increasing permeability; multiple step fracture; enhanced extraction

DOI: 10.13800/j.cnki.xakjdxxb.2015.0305

备注

新河煤矿为煤与瓦斯严重突出的基建矿井,煤层透气性低、瓦斯含量高。采用顶板抽放巷下向穿层钻孔进行预抽煤层瓦斯,抽采效率低,条带消突周期长。为提高新河煤矿抽采效果,先后尝试了水力压裂、水力冲孔增透措施,抽采效率有所改善,但持续时间短。在现场实践的基础上,提出了水力压冲一体化技术,以“水力压裂单元增透,水力冲孔出煤卸压”为技术思路,探讨了其技术流程、卸压增透及多级裂缝的形成机理,通过现场水力压冲增透抽采试验,结果表明,水力压裂后进行水力冲孔,瓦斯涌出严重,平均单孔涌出瓦斯1 485 m3,是未进行水力压裂的4.9倍,试验后最大日抽采纯量1 731 m3/d,平均623 m3/d,是试验前的2.9倍。

Xinhe mine is a coal and gas outburst constructing mine,characterized as its low permeability and high gas content.When the downward borehole in the roof tunnel is used to extract gas for safety of the later coal tunneling,the extraction efficiency is low and period of eliminating outburst is long.Therefore,in order to improve the extraction effect in Xinhe mine,hydraulic fracturing and hydraulic flushing are used to enhance the coal permeability,and then the extraction efficiency was increased,however,the effect can not maintain for long time.In this paper,the authors presented hydraulic and flushing integration technology based on practice,which relies on the technical ideas of hydraulic fracturing to increase the unit permeability and hydraulic flushing to rush out coal and release the pressure.Besides,the technological process was discussed,and the forming mechanism of pressure relief,permeability increase and multiple step fracture was clarified.The experiment of hydraulic fracturing and flushing showed that gas gushed seriously during hydraulic flushing and erupted 1 485 m3 per borehole,which is 4.9 times of before the hydraulic fracturing.The maximum extraction volume of pure gas is 1 731 m3/d and the average is 623 m3/d,which is 2.9 times of before the experiment.