Background The geological conditions of coalbed methane(CBM) (coal mine gas) in China's coal mine area are complex, and it is for a single technology to achieve the effect of efficient resource extraction and effective disaster management.

Advances  According to the current situation of the application of CBM (coal mine gas)extraction technology China in recent years, the mining methods are divided into three categories: ground extraction, underground extraction, ground and underground combined extraction according to the spatial layout, and according the time layout, The first two extraction are divided into ground preliminary extraction, underground preliminary extraction, ground pressure relief extraction, and underground pressure relief extraction. On this basis, the main extraction technologies and their characteristics contained in different types are compared and analyzed. Among them, the types of ground preliminary extraction mainly include vertical well (group well), remote end docking horizontal well, multi-branch horizontal well and sectional fracturing horizontal well technology, the types of ground well pressure relief extraction mainly include vertical well and L well technology, and the types of underground preliminary extraction mainly include along-layer drilling technology, cross-layer drilling technology and umatic directional drilling technology. The types of underground pressure relief extraction mainly include cross-layer drilling technology and high-position directional drilling technology. The connotation of ground and underground combined extraction is the underground directional long borehole communicate the range of ground fracturing of ground well. According to the characteristics of the geological conditions and coal engineering conditions applicable to various types of extraction technology, the application effect of each technology in the demonstration project is analyzed with representative coal mines as examples. The horizontal well technology of segmented fracturing and the ground L well technology are considered to be the efficient technology of the preliminary extraction and the pressure relief extraction on the ground, and it is proposed that the main factors controlling the quality and the effect of the underground preliminary extraction and the pressure relief extraction are the directional drilling process and its technical level.

Prospects  Based on the trend of China's coal mine area coal and CBM (coal mine gas)industry, four key directions for the future development of CBM (coal mine gas)technology in coal mine area are proposed. It mainly includes ground and underground combined extraction technology, deep CBM and coal resources coordinated exploration and development technology, multi-disaster management technology, and closed mines gas resources recycling utilization technology.