割缝与压裂协同增透技术参数数值模拟与试验

发布时间：2019-05-12 06:53

【摘要】：针对古汉山矿低透气性煤层穿层抽采钻孔卸压不充分的问题,提出了割缝与压裂协同增透技术,基于弹性断裂力学和Biot经典渗流力学理论,采用数值模拟的方法,分析了割缝钻孔与压裂钻孔协同布置时不同条件下压裂裂缝扩展规律,确定割缝钻孔与压裂钻孔水平距离为4 m时压裂效果较好,缝槽相对于水平方向的倾角应避免为45°,割缝钻孔形成的缝槽可以控制压裂裂缝的扩展方向,裂缝影响范围内应力由约8 MPa下降至4 MPa以内。现场试验表明,距割缝钻孔2 m以内的煤体发生了位移,协同割缝钻孔的瓦斯抽采纯量是割缝钻孔的2.3倍,是普通钻孔的7.8倍,协同压裂钻孔的瓦斯抽采纯量是压裂钻孔的2.1倍,普通钻孔的5倍,瓦斯抽采效率显著提高。
[Abstract]:In order to solve the problem of insufficient pressure relief in the drilling hole of low permeable coal seam in Guhanshan Mine, the cooperative antireflective technology of slit and fracturing is put forward. Based on the elastic fracture mechanics and Biot classical seepage mechanics theory, the numerical simulation method is adopted. The fracture propagation law under different conditions is analyzed when the joint drilling and fracturing boreholes are arranged together. It is determined that the fracturing effect is better when the horizontal distance between the slit drilling and the fracturing hole is 4 m, and the dip angle of the slot relative to the horizontal direction should be avoided to 45 掳. The fracture groove formed by slit drilling can control the propagation direction of fracture, and the stress in the influence range of fracture decreases from about 8 MPa to less than 4 MPa. The field test shows that the coal body within 2 m from the slit hole has been displaced, and the pure amount of gas extraction in the cooperative seam hole is 2.3 times as much as that in the slit hole and 7.8 times as much as that in the ordinary hole. The pure amount of gas extraction in cooperative fracturing hole is 2.1 times as much as that in fracturing hole and 5 times as much as that in ordinary hole, and the gas extraction efficiency is significantly improved.
【作者单位】：中国矿业大学安全工程学院;中国矿业大学煤炭资源与安全开采国家重点实验室;
【基金】：国家重点基础研究发展计划(973)资助项目(2011CB201205) 国家科技支撑计划资助项目(2012BAK04B07) 国家自然科学基金资助项目(51204174)
【分类号】：TD712.6

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