Application of Tight Radius Drilling in Draining Methane from Low Permeability Coal
Methane in coal poses a very real risk to underground mining operations, being both a source of explosions and also outbursts. The problems of coal and gas outburst have become a key factor influencing secure production in the main local producing countries over the world. The most effective way to minimize the risk of methane explosion or outburst is to remove the gas from the coal prior to mining. 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 Australias Grasstree Mine, for the purpose of pre-draining methane from the German Creek seam prior to underground mining. 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 900,000m3 of gas removed and reducing the inseam gas content from an average of 7.8m3/t to an estimated 3.7m3/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.
Draining Methane Tight Radius Drilling Coal and Gas Outburst Low Permeability Coal
LU Yiyu CHENG Jun LI Xiaohong KANG Yong LAN Huaju
Education Ministrys Key Lab for the Exploitation of Southwestern Resources & Environmental Disaster Control Engineering, Chongqing University, Chongqing, 400044 China
国际会议
The 2007 International Symposium on Safety Science and Technology(2007采矿科学与安全技术国际学术会议)
河南焦作
英文
1569-1574
2007-04-17（万方平台首次上网日期，不代表论文的发表时间）