深部高瓦斯强突煤层水力化压-割联合抽采有效半径研究

Research on Effective Radius of Hydraulization Pressure-cutting Combined Extraction in Deep High Gas and Strong Outburst Coal Seams

  • 摘要: 深部煤层开采受高瓦斯压力和高瓦斯含量等因素影响,致使瓦斯预抽钻孔施工成本高,瓦斯抽采效率低。为提高深部高瓦斯强突煤层透气性,优化穿层钻孔施工工艺,对水力化压-割联合卸压增透技术瓦斯抽采有效半径展开研究。研究结果表明:不同水力化措施下,水力化压-割联合卸压增透技术相较单一水力压裂和水力割缝技术,抽采浓度分别提升1.47倍和1.25倍,单孔平均抽采纯量分别提升2.04倍和1.32倍;不同抽采半径钻孔布置下,3.5 m抽采半径钻孔平均抽采浓度达48.85%,平均单孔瓦斯抽采纯量达0.025 7 m3/min,瓦斯压力平均降幅达88.3%,节约施工成本的同时实现了较优的瓦斯抽采效果。该研究对深部高瓦斯强突煤层水力化卸压增透措施穿层钻孔布置具有一定参考意义。

     

    Abstract: Deep coal seam mining is affected by factors such as high gas pressure, high gas content and others, resulting in high construction costs and low gas extraction efficiency of gas pre-extraction drilling. In order to improve the permeability of deep high gas and strong outburst coal seams and optimize the construction process of through layer drilling hole, a study is carried out on the effective radius of gas extraction of hydraulization pressure-cutting combined pressure relief and permeability enhancement technology. The research results show that under different hydraulization measures, the hydraulization pressure-cutting combined with pressure relief and permeability enhancement technology improves the extraction concentration by 1.47 times and 1.25 times respectively compared to single hydraulic fracturing and hydraulic cutting technologies, and the average extraction purity per hole is improved by 2.04 times and 1.32 times respectively; Under different hole arrangements with different extraction radii, the average extraction concentration of the hole with 3.5 m extraction radius reaches 48.85%, the average gas extraction purity per hole reaches 0.025 7 m3/min, and the average decrease of gas pressure reaches 88.3%. This not only saves construction cost but also achieves better gas extraction effect. This study has certain reference significance for the arragements of through layer drilling holes of hydraulization pressure relief and permeability enhancement measures in deep high gas and strong outburst coal seams.

     

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