山西省废弃矿井采空区煤层气地面抽采实践

历史上部分中小煤矿受回采工艺、技术等限制,采空区遗留有大量煤炭,所释放煤层气(瓦斯),对安全生产造成影响;部分煤层气通过上覆地表裂隙散放至大气中,造成环境污染。针对上述安全、环境及社会问题,以山西省废弃矿井采空区煤层气治理为工程背景,提出了废弃矿井采空区煤层气地面钻采技术及配套工艺体系。即使用惰性气体如氮气等作为地面钻井循环介质,安全揭露采空区顶板裂隙带及垮落带,根据煤层气浓度通过增压机组等设备进行负压抽采,实现分级抽采利用废弃矿井采空区煤层气的目的。应用实践表明,采空区地面井平均产能达2000m^3/d,部分高产井产能甚至达到6000m^3/d,抽采年限达6年以上。

Practice of Coalbed Methane Surface Extraction in Goaf of Abandoned Mine in Shanxi Province

Historically, some small and medium-sized coal mines are limited by mining technology and technology. There are a lot of coal left in the goaf, and the released coalbed methane(gas) has an impact on the safety of production;some coalbed methane is released into the atmosphere through the overlying surface fractures, causing environmental pollution. In view of the above safety, environmental and social problems, based on the engineering background of the treatment of coalbed methane in the goaf of abandoned mines in Shanxi Province, the surface drilling and mining technology and supporting technology system of coalbed methane in the goaf of abandoned mines are put forward. That is to say, inert gas such as nitrogen is used as the circulation medium of surface drilling, the roof fracture zone and caving zone in the goaf are exposed safely, and the negative pressure extraction is carried out through the supercharger unit and other equipment according to the concentration of coal-bed methane, so as to realize the purpose of hierarchical extraction and utilization of coal-bed methane in the goaf of abandoned mine. The application practice shows that the average production capacity of surface wells in goaf is 2000 m^3/d, the production capacity of some high-yield wells even reaches 6000 m^3/d, and the extraction life is more than 6 years.