采煤工作面顺层钻孔分段水力压裂增渗试验

低透气性突出煤层顺层钻孔预抽回采工作面瓦斯具有工程量大,抽采效率低等特点,为此,采用顺煤层分段水力压裂实现煤储层增透。寺家庄矿15#煤层属于低透气性突出煤层,在15301工作面开展了顺煤层分段水力压裂强化抽采试验,利用自主研发的拖动式双封隔器分段封孔装备及工艺,满足压裂孔稳定、快速封隔,可实现全孔段分三段及以上逐级开展压裂。对比压裂区和非压裂顺层钻孔瓦斯抽采效果,压裂区平均浓度为35.1%,非压裂区为6.0%,压裂区浓度是非压裂区的5.9倍;压裂区百孔纯量为3.6 m3/min,非压裂区为0.3 m3/min,压裂区百孔纯量是非压裂区的11.2倍。

Permeability enhancement test of staged hydraulic fracturing of bedding drilling borehole in working face

In low permeability and outburst coal seam, the gas in the working face extracted by bedding drilling borehole has the characteristics of large amount of workload and low extraction efficiency. No.15 coal seam of Sijiazhuang Coal Mine belongs to the low permeability outburst coal seam. Staged hydraulic fracturing of bedding drilling borehole was carried out to enhance the extraction in 15301 working face. By using the self-developed drag type double packer section sealing equipment and technology,the fracturing hole can be stably and rapidly sealed, and the whole hole section can be divided into three or more sections for fracturing. Compare the gas drainage effect of drilling in fracture zone and non-fracture zone, the average concentration of fractured area is 35.1%, and that of non-fractured area is 6.0%. The concentration of fractured area is 5.9 times of that of nonfractured area. The pure flow rate of 100 holes in fractured area is 3.6 m3/min, and that in the non-fractured area is 0.3 m3/min.The pure flow rate of 100 holes in the fractured are is 11.2 times of that in the non-fractured area.