Zegong Liu

1. Introduction Click to copy section linkSection link copied! Coal is the fundamental and most-used source of energy in China. As an efficient and clean resource associated with coal, methane’s efficient extraction is the fundamental method for preventing and controlling methane-related disasters and accidents, as well as obtaining clean energy. (1,2) China’s coal seam structure is complex, and coal permeability is generally low.

1. Introduction The earliest experiments on coalbed methane drainage by surface wells (CDSW) in China were conducted in No. 4 Coal Mine of Yangquan Mining Group in 1956 [1,2]. CDSW, which is a key technology for realizing the co-mining of coal and coalbed methane (CBM), has been widely adopted in highly gassy coal fields currently. According to the literatureon gas, the CDSW technology can be classified into the following two categories.