分段多簇密切割压裂技术在淮南矿区煤层气抽采中的应用

Application of Staged Multi-cluster Dense-cutting Fracturing Technology in Coalbed Methane Extraction in Huainan Mining Area

针对淮南矿区碎软低渗煤层瓦斯抽采技术难题,以13-1煤层为例,在分析煤层及其顶底板概况的基础上,采用煤层顶板分段压裂水平井技术,充分利用水平井水平段,单段分3簇射孔,簇间距25 m,实现分段多簇密切割体积压裂改造。微地震监测结果表明,单段裂缝长度102.5~211.4 m,缝高17.3~27 m,裂缝主体向下延伸,实现了井筒与煤层的沟通。排水采气效果表明,最高产气量1519 m^(3)/d,取得了良好的产气效果。研究成果为淮南矿区煤层气地面预抽和瓦斯区域治理提供了工程借鉴。

Aiming at the technical problem of coalbed methane(CBM)extraction of broken-soft coal seamsin Huainan mining area,taking 13-1 coal sem as an example,based on the analysis of the general situation of target coal seam and its roof and floor,the staged fracturing technology of horizontal well in coal seam roof is applied.And the horizontal section of horizontal well is fully utilized.There are three clusters in each stage,and the cluster spacing is 25 m,so as to realize the staged multicluster dense-cutting volume fracturing stimulation of coal seam.The microseismic monitoring results show that the length of single-stage fracture is between 102.5 m and 211.4 m,the height is between 17.3 m and 27.0 m.The main fracture extends downward and the communication between wellbore and coal seam is realized.The effect of drainage gas recovery shows that the maximum daily gas production is 1519 m3/d,and good gas production effect was achieved,which provides engineering reference for ground pre-drainage of coalbed methane and regional gas control in Huainan mining area.