摘要
针对在瓦斯渗透率低的煤层中现有的瓦斯抽放方式效率很低的问题,澳大利亚的Grasstree煤矿进行了极小转弯半径钻井系统现场试验.试验采用地面瓦斯抽放方法的极小转弯半径钻井系统能够沿着常规中心竖井在不同埋深的煤层中呈辐射状以极小转弯半径钻进多条深长水平孔,钻进水平瓦斯抽放孔总长1300m,其中最长的182m.试验结果表明,约抽放出900000m3瓦斯,将煤层中瓦斯含量从7.8m3/t减少至3.7m3/t.Grasstree煤矿试验证明极小转弯半径钻井系统在地下煤层瓦斯抽放、减小煤矿瓦斯灾害方面具有很好的应用前景.
Many of these coal seams have low gas permeability, making economical extraction of coal gas resource difficult. The Tight Radius Drilling （TRD） system for surface extraction of gas from coal seams is capable of drilling multiple lateral holes, which radiate out from a central conventional drilled vertical well, One TRD well has been drilled at Anglo Australia＇s Grasstree Mine, for the purpose ofpre-draining methane. A total of 1300 meters of laterals were drilled, with the longest lateral being 182 meters. It is apparent that the hole performed well with about 900,000 m^3 of gas removed and reducing the inseam gas content from an average of 7.8 m^3/t to an estimated 3.7 m^3/t. The well drilled at Grasstree proved an invaluable development ground for the TRD technology, with numerous significant advancements to the state of the system being made.
出处
《河北工业大学学报》
CAS
2007年第6期28-31,共4页
Journal of Hebei University of Technology
基金
国家自然科学基金(50604019)
重庆市自然科学基金重点项目(2005ba0411)
关键词
高压水射流
瓦斯抽放
极小转弯半径钻井
煤与瓦斯突出
低渗透率煤层
high pressure water jet
draining methane
tight radius drilling： coal and gas outburst
low permeability coal
