针对低透气性煤层瓦斯抽采效率低、钻孔施工量大等问题,提出了水力压裂增透技术,研究了水力压裂增透机理,分析了水力压裂提高煤层透气性的过程,确定了设备仪器与压裂工艺参数,完成了高压钻孔密封与现场水力压裂,并对瓦斯抽果效果和煤层透气性系数变化进行了考察。结果显示:实施水力压裂后,瓦斯抽采量提高了7.2倍,水力压裂影响区域内煤层透气性系数提高了79~272倍,达到了增大煤层透气性,提高瓦斯抽采效率的目的。
According to the low gas drainage efficiency of the low permeability seam, high construction load of the boreholes and other problems, a hydraulic fracturing and permeability improvement technology was provided. The hydraulic fracturing and permeability improvement mechanism was studied. The process of the hydraulic fracturing to improve the permeability of the seam was analyzed. The parameters of the equipment instrument and fracturing were determined. The high pressure borehole sealing and the site hydraulic fracturing was completed. The investigation was conducted on the gas drainage effect and the seam permeability coefficient variation. The results showed that after the hydraulic fracturing completed, the gas drainage value was improved by 7. 2 times and the permeability coefficients of the seam within the hydraulic fracturing influence area could be improved by 79 - 272 times. Thus the target to improve the seam permeability and to improve the gas drainage efficiency could be reached.