复杂地层大直径高位定向钻孔代替高抽巷瓦斯抽采可行性及效果分析

针对高抽巷瓦斯抽采存在施工成本高、周期长、劳动强度大等问题，开展在复杂地层中采用定向钻机施工大直径高位定向钻孔代替高抽巷的技术研究，并形成 “定向先导孔+正向分级扩孔”成孔工艺，确保特殊地质条件下大孔径钻孔的成孔率。赵庄煤业在3307和1309工作面施工大直径高位定向钻孔，最大孔深突破600 m，最大孔径203 mm。1309工作面大直径高位定向钻孔单孔最高日抽采量突破3.3万m³，单个钻场最高日抽采量突破5万m³，与高抽巷瓦斯治理能力相当，证明了复杂地层条件下定向钻机施工大直径高位定向钻孔代替高抽巷抽采瓦斯的可行性。结合“竖三带”和椭抛带理论，对大直径高位定向钻孔最佳布孔范围进行了分析和确定。

Gas extraction feasibility and effect analysis of large diameter and high directional drilling in complicated strata instead of high drainage roadway

Aiming at the problems of high construction cost，long cycle and high labor intensity in hig drainage gas drainage technology，the research on the use of directional drilling machine to construct large diameter high position directional drilling instead of high drainage roadway in complex stratum was carried out，and the orientation was formed."Pilot hole + forward graded reaming" hole forming process to ensure the hole formation rate of large aperture drilling under special geological conditions.Applied to 3307 and 1309 working faces，the maximum hole depth exceeded 600 m and the maximum hole diameter was 203 mm.The maximum daily extraction volume of the large diameter high position directional drilling hole of 1309 working face exceeded 33 000 m³，and the maximum daily extraction volume of a single drilling field exceeded 50 000 m³，which was equivalent to the gas control capacity of high drainage roadway.The directional drilling machine construction of large diameter and high directional drilling instead of high drainage roadway was proved feasibility of complex stratum conditions.Combining the theory of "vertical three belts" and elliptical belts，the optimal cloth hole range of large diameter and high position directional drilling wais analyzed and determined.