Guizhou Panjiang Coalbed Methane Development and Utilization Co., Ltd.
Guizhou Coalbed Methane and Shale Gas Engineering Technology Research Center
Guizhou Coalfield Geology Bureau, No. 159 Team

贵州煤炭资源量大，经长期开采，形成大面积采空区，采空区下伏煤层气资源量丰富，但开发利用率低。主要原因为贵州地区地面条件复杂、煤系地层纵向跨度大、煤层发育具有多薄等特点。在采空区钻井抽采上覆煤层卸压瓦斯及下伏煤层气时，采用常规钻井技术成井较为困难，易发生井下复杂事故，导致贵州地区对煤矿采空区内煤层气资源的开发利用较少。为了抽采采空区上覆煤层卸压瓦斯及充分利用采空区下伏煤层煤层气资源，探索多煤层采空后上覆煤岩层叠置“三带”在纵向发育特征及底鼓煤岩层应力变化规律就显得尤为重要。以贵州盘江矿区山脚树矿为例，实施1口过采空区多煤层定向试验井。结果表明：在贵州特殊地质条件下在煤矿采空区实施定向井抽采上覆煤层气卸压瓦斯及下伏煤层煤层气具有很好的经济性。同时通过该井的成功实施，首先探明了盘江矿区多煤层采空后“叠置”三带在纵向上的发育特征，其次成功获取了煤矿采空区下伏煤层煤层气抽采关键地质及工程技术参数，实现了采空区煤层气资源利用最大化，为后续在盘江矿区乃至整个贵州地区开展采空区瓦斯卸压抽采及下伏煤层煤层气开发提供了宝贵的工程经验和技术支撑。

Guizhou has a large amount of coal resources, which have been mined for a long period of time, resulting in the formation of a large area of goaf. There is a large amount of coalbed methane resources in the goaf, but the exploitation and utilization rate are low, mainly because of the complex ground conditions, the large longitudinal span of coal measure strata, and the thin development of coal seam in Guizhou. When extracting pressure relief gas from overlying coal seam and coalbed methane from goaf using drilling wells passed through goaf, it is difficult to form wells using conventional drilling technology and is prone to complex underground accidents, which leads to less exploitation and utilization of gob coalbed methane resources in Guizhou. In order to extract pressure relief gas from the overlying coal seam and make full use of the goaf coalbed methane resources, it is particularly important to explore the longitudinal development characteristics of the superimposed “three zones” of overlying coal strata and the stress variation law of the bottom bulge coal strata after multi-seam mining. Taking Shanjiaoshu Mine, Panjiang mining area, Guizhou as an example, a directional test well passing through goaf with multiple coal seams was carried out. The results shown that the implementation of directional well to extract pressure relief gas from overlying coal seam and underlying goaf coalbed methane under special geological conditions in Guizhou had great economics. Meanwhile, through the successful implementation of the well, the longitudinal development characteristics of the superimposed “three zones” in Panjiang mining area after multi-seam mining were firstly verified. Secondly, the key geological and engineering technical parameters of coalbed methane extraction from the underlying coal seam in the coal mining goaf were also successfully obtained, and the utilization of coalbed methane resources in the goaf had been maximized. The project provided valuable engineering experience and technical support for the subsequent development of extracting pressure relief gas in gob and coalbed methane from underlying coal seam in Panjiang mining area and even in the whole Guizhou region.

贵州省科技计划资助项目(黔科合战略找矿﹝2022﹞ZD001)；贵州省科技计划资助项目（黔科合支撑﹝2020﹞2Y028）

娄　毅，梁龙军，陈　捷，等. 过采空区叠置“三带”定向钻井技术研究[J]. 煤炭科学技术，2023，51（11）：148−157.

LOU Yi，LIANG Longjun，CHEN Jie，et al. Research on directional drilling technology for superimposed “three zones” passing through goaf[J]. Coal Science and Technology，2023，51（11）：148−157.