Control Characteristics of Two Major Geological Factors on Gas Occurrence of Qi'nan Coal Mine

To make coalbed gas of Qi'nan Mine get more effective extraction and achieve better control effect, we studied their control characteristics of two major geological factors of controlling gas occurrence of tectonic evolution and hydrodynamic conditions on coalbed gas of Qi'nan Coal Mine. Studies show that the return and lifting of the tectonic evolution control the gas generating characteristics, especially the thermogenic gas and secondary biogenic gas, and judging secondary biogenic gas become the main cause of coal seam gas of Qi'an 7₂ coalbed; in the overall, hydrological dynamic of 7₂ coalbed gas of Qi'nan Coal Mine has play an important role on hydraulic seal, making the gas concentration in coalbed, this is the main reason that 7₂ coalbed gas content of Qi'nan Coal Mine is higher than the adjacent and similar mine coalbed. On the local, hydraulic migration and dissipation function on coallbed gas migration of the segment Ⅱ has control effect, and the hydraulic closed effect on coalbed gas occurrence has certain influence.