坚硬顶板超前区域治理技术在神东布尔台煤矿的应用

Application of advanced regional treatment technology of hard roof in Buertai Coal Mine of Shendong Coal Group

  • 摘要: 坚硬顶板是岩层控制的一大难题,高位坚硬岩层的破断失稳经常会诱发强矿压灾害,严重威胁矿井的安全生产,坚硬顶板的治理是煤矿安全生产的重大难题之一。针对神东矿区布尔台煤矿煤层顶板厚度大、硬度高、垮落难等问题,分析定向长钻孔分段水力压裂的压裂机理和技术优势,基于关键层理论确定了钻孔布置层位,采用拟三维裂缝模型对压裂注入时间和注入流速对裂缝扩展的影响进行分析计算,确定布尔台煤矿42108工作面顶板压裂钻孔布置方式,沿工作面倾向方向平行布孔3个,裂缝半长41 m,压裂控制区域覆盖了整个工作面。实践表明:42108工作面在实施了坚硬顶板分段水力压裂弱化后,工作面正常支架循环末阻力同比下降3.33%;周期来压期间,支架循环末阻力同比下降6.81%;动载系数平均降低了10.88%;强矿压显现减弱,保证工作面安全回采。

     

    Abstract: The hard roof is a difficult problem in rock stratum control. The breaking and instability of high hard rock strata often induces strong coal pressure disasters, seriously threatening the safety production in coal mines. Hard roof control is one of the major problems in coal mine safety production. In response to the problems of large thickness, high hardness of the coal seam roof and its difficulty in collapse in Buertai Coal Mine in Shendong Mining Area, the hydraulic fracturing mechanism and technical advantages of directional long borehole segmented hydraulic fracturing are analyzed. The location of boreholes is determined based on the key layer theory. The effects of fracturing injection time and injection velocity on fracture propagation are analyzed and calculated by using the pseudo three-dimensional fracture model. The layout of the roof fracturing boreholes of 42108 working face in Buertai Coal Mine is determined, where three holes are arranged in parallel along the inclined direction of the working face. As the half length of the fracture is 41 m, the fracturing control area covers the whole working face. The practice shows that after the application of segmented hydraulic fracturing, the end cycle resistance of normal support in working face decreases by 3.33% in 42108 working face. During the period of cyclic pressure, the end cycle resistance of the support decreases by 6.81%. The dynamic load coefficient reduces by 10.88% on average. It weakens the strong coal pressure behavior of the mine, ensuring the mining safety of the working face.

     

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