Document Type

Conference Paper

Publication Date


Publication Details

Y. Cheng, H. Wang and L. Wang, Regional Gas Drainage Techniques and Applications in Chinese Coal Mines, 11th Underground Coal Operators' Conference, University of Wollongong & the Australasian Institute of Mining and Metallurgy, 2011, 335-342.


With China’s rapid and sustained development of economy, the demand for coal supply has resulted in the extraction of coal in deeper coal mines, particularly in China’s economically developed Eastern region where many mines have started mining at depths between 800 and 1500 m. As the depth increases, the geo-stress, pressure and gas content of coal seam also increases, and the geological conditions become more complicated with lower-permeability and softer coals, thus coal and gas outbursts and gas explosions and other hazards become increasingly serious. In order to effectively prevent gas disasters, the National Engineering Research Centre of Coal Gas Control, together with the Huainan and Huaibei Mining Group, have developed a regional system of gas extraction technology and conducted theoretical and experimental research. The results include: a) under multi-seam conditions, a relatively low gas disaster-prone coal seams can be mined as the first key protective layer, which can lead to stress-relief, and increased permeability by 400 to 3 000 times, thus facilitating the desorption and accumulation of gas flow; b) in a single seam, the use of enhanced extraction boreholes (crossing boreholes and in-seam boreholes) combined with hydro-fracturing greatly increases coal seam gas extraction rates up to 50%. Engineering practice has proved that the regional gas drainage technology not only eliminates the regional coal and gas outburst threat, but also enables gassy seam mining with low gas emissions. The research results have been adapted by China's national safety codes of production technology. This paper introduces the technology principles, engineering practices as well as the key parameters of regional gas drainage for engineering applications.