Technical Methods of Safe High-efficient Exploitation of Coal and Gas Together in High-gas Coal Seams in China

There are many coal seams in high-gas mining area of China. The permeability is low. The gas extraction from the original coal seam is difficult and the commercial value is little. The conception of the safe high-efficient exploitation of coal and gas is put forward in this article. It changes the conventional exploitation sequence that is from the upper to below. When we exploit coal seams, the initial coal seam with low gas content and without coal and gas outburst danger is exploited firstly. Then the permeability of the coal seams increases greatly making use of the exploiting effect. The gas effusion can be divided into short-distance gas emission, intermediate-distance gas emission and long-distance gas emission according to the difference of the comparative interval. The high-efficient gas extraction method is adopted to realize the high-efficient extraction of the gas resource. The high-efficient extraction of the gas resource affords advantageous condition to the safe high-efficient exploitation of the coal resource. Consequently the safe high-efficient exploitation of the coal and gas resources can be realized. The practice of the long-distance gas extraction and the safe high-efficient exploitation of coal and gas in the mining area of Huainan China proves that the safe high-efficient exploitation of coal and gas is the important technical method of the safe high-efficient exploitation of coal and gas together in high-gas coal seams.