套管钻进技术在煤矿复杂地层中的应用探讨

我国的地质条件和煤层特征差异大,复杂地层中构造煤发育,瓦斯含量高,地应力大,煤层破碎松软,易发生塑性流变。采用套管钻进技术替代传统的常规钻杆进行钻孔瓦斯抽采,可提高工作效率,防止卡钻、塌孔等事故的发生,提高瓦斯抽采的效率,并可以不起钻取出钻头等孔底钻具组合下筛管,解决在井下复杂地层中钻孔瓦斯抽采的难题。介绍了套管强度及孔底组合钻具结构,探讨了套管钻进技术在煤矿复杂地层中的应用前景。

Discussion on Application of Casing Drilling Technology in Complex Formation of Coal Mine

The geological conditions and coal seam characteristics have many differences in China. The complex formation has many characteristics, such as tectonic coal, high content of gas, high geostatic stress and the broken soft coal seam where plastic flow easily occur. Casing drilling technology is adopted to replace the traditional drill pipe for borehole gas extraction, the work efficiency and gas extraction rate were improved. It also can prevent many accidents, such as sticking and hole collapsing, and remove the bottom tool assembly without pulling the drill pipe out. Casing strength and bottom tool assembly were introduced and the application prospect of casing drilling technology in complex formation of coal mine is discussed.