首山一矿采空区地面高效抽采煤系气井优化设计

Optimization Design of Coal Measures Gas Well with High Efficiency Surface Extraction in Goaf of Shoushan No.1 Coal Mine

以平顶山矿区的首山一矿为研究对象,采用地层综合柱状、采动三带分布特征、气测录井和“O”形圈理论相结合的方法,对采空区地面抽采井的井位、层位、井身结构、抽采工艺等进行了优化设计,并对其抽采效果进行了评价。结果表明:由“三开结构”代替传统的“二开结构”,有效防止了含水层水向钻井中的漏渗,保证了产气通道的畅通性;延长了“三开筛管层段”,实现了煤系“多气源”的高效抽采;加大抽采管径并实施分级负压抽采,减小了抽采管路摩阻,提高了抽采效率。截至2022年11月底,气井平均日抽采量、甲烷浓度和累计抽采量分别为7 210 m^(3)/d、69.55%和375万m^(3),日产气量持续保持稳定。优化的首山一矿采空区高效抽采煤系气井关键环节,为类似地质条件矿井采空区地面抽采提供了借鉴和指导。

Taking Shoushan No.1 mine in Pingdingshan mining area as the research object, the method combining stratigraphic comprehensive column, distribution characteristics of mining three zones, gas logging and "O" circle theory was used to optimize the design of well location, layer, well structure and extraction process of surface extraction wells in the mining area, and the extraction effect was evaluated. The results show that the traditional "two-open structure" is replaced by the "three-open structure", which effectively prevents the leakage of water from the aquifer into the drilled well and ensures the smoothness of the gas production channel;the "three-open screen pipe section" is extended, which achieves the "three-open" coal system. The extension of the "three-open screen pipe section" has realized the efficient extraction of "multiple gas sources" in the coal system;the increase of the extraction pipe diameter and the implementation of graded negative pressure extraction have reduced the friction of the extraction pipeline and improved the extraction efficiency. By the end of November 2022, the average daily extraction volume, methane concentration and cumulative extraction volume of gas wells were 7 210 m^(3)/d, 69.55% and 3.75 million m^(3), respectively, and the daily gas production volume remained stable. The optimized key aspects of efficient extraction of coal-based gas wells in the mining hollow area of Shoushan No.1 mine provide reference and guidance for surface extraction in the mining hollow area of mines with similar geological conditions.