寺河井田下组煤煤层气开发有利区优选及穿煤柱水平井井位部署

寺河井田在煤炭开采前需要通过地面预抽方式降低瓦斯含量以解决煤炭开采过程中的瓦斯突出等问题。煤矿区地面煤层气开发工程要做到与煤炭的协调开发，煤层气抽采区块的优选及井位的合理部署至关重要。本文利用FLAC3D软件模拟，建立煤层底板采动效应地质模型，开展针对性的研究上组煤采动后下伏岩层应力变化；结合煤矿采掘部署，选取下组煤煤层气开发的主控因素为指标，建立采动区下组煤煤层气开发潜力评价指标体系，采用层次分析法和模糊综合评价相结合的方法，评价煤层气开发的有利区块；以煤层气与煤炭协调开发为前提，确定穿煤柱水平井煤层气开发井位部署的原则，研究水平井设计的关键要素及内容，优化设计15口井位。研究表明：9号煤层和15号煤层都处在3号煤层开采卸压范围内；东五盘区是寺河井田部署下组煤煤层气水平井的优选区，开展的1口煤层气井最高日产气量达到了9 522 m3。

Optimization of CBM extraction area from the lower group coal and Deployment of coal pillars horizontal well in the Sihe coalmine

It is necessary to reduce the gas content by pre-drainage of ground gas before coal mining to solve the problem of gas outburst in coal mining process of Sihe coalmine. In order to coordinate the development of CBM (coalbed methane) in coal mining area, the optimization of CBM extraction block and the reasonable deployment of well locations are crucial. In the study, the FLAC3D software was used to simulate the geological model of mining effect of coal floor, and the stress change of the underlying rock strata after mining of upper group coal was studied. Combined with the mining deployment of coal mine, the main controlling factors of coalbed methane horizontal well development of lower group coal were selected as indicators, and the evaluation index system of CBM development potential of lower group coal in mining area was also established. The method of analytic hierarchy process and fuzzy comprehensive evaluation were combined and used to evaluate the favorable blocks of CBM development. On the premise of the coordinated development of CBM and coal, the principle of CBM extraction through coal pillars horizontal well placement was determined, the key elements and contents of horizontal well design were studied, and the placement of 15 horizontal wells was optimized. The research shows that No. 9 coal seam and No. 15 coal seam are in the mining and pressure relief range of No. 3 coal seam; Dongwupan of Sihe mine is an excellent selection for the deployment of lower group CBM horizontal wells in Sihe well field. The highest daily gas production of one-well CBM conducted reaches 9522 m3.