贵州新田矿区顶板L型水平井煤层气抽采技术

Coalbed Methane Extraction Technology of Roof L-type Horizontal Well in Guizhou Xintian Mining Area

针对碎软煤层瓦斯灾害频发、瓦斯抽采困难、顺煤层水平井钻进困难的问题,在借鉴“虚拟储层”思路和页岩气开发技术的基础上,以新田矿区9号煤层为对象,研究分析了煤层顶板L型水平井分段压裂抽采技术。通过目标区及目标层位优选、井身结构优化、井眼轨迹精准控制技术、多簇定向射孔分段压裂精确优化工艺技术及排采作业精细控制技术,形成了煤层顶板L型水平井煤层气高效抽采技术体系。结合工程实践,顶板L型水平井在新田矿区取得了产能突破,最高日产气量达到了5334 m^(3)/d,并获得了长期稳产高产的试验结果。顶板L型水平井分段压裂高效抽采技术的成功应用,为具有类似地质条件的高突矿井煤层气抽采及煤矿区瓦斯治理提供了技术方向引领。

Aiming at the problems of frequent gas disasters in crushed and soft coal seams,difficulty in gas extraction,and difficulty in drilling horizontal wells along coal seams.Based on the method of"virtual reservoir"and the technology of shale gas exploitation.Taking No.9 Coal Seam in Xintian Coal Mine as the object,the staged fracturing drainage technology of L-type horizontal well in coal seam roof is studied and analyzed.The high-efficiency CBM extraction technology system of L-type horizontal well in coal seam roof is formed by the optimization of target area and target horizon,the optimization of wellbore structure,the precise control technology of wellbore trajectory,the precise optimization technology of multi-cluster directional perforation and staged fracturing,and the fine control technology of drainage operation.Combined with the application of engineering practice,the roof of L-type horizontal well has achieved a breakthrough in production capacity in Xintian Coal Mine,and the maximum daily gas production has reached 5334 m^(3)/d,the test results of long-term stable and high yield had been obtained.A technical direction leading is provided for CBM extraction and gas control in high outburst mines with similar geological conditions,which by the successful application of high-efficiency extraction technology of stage fracturing of L-type horizontal well in coal seam roof.