Coal mine gas migration model establishment and gas extraction technology field application research.

• A gas migration-diffusion model was constructed. • The optimization scheme of gas extraction parameters were discussed. • The effects of parameters on the extraction effect were investigated. Gas drainage is the main technical measure to prevent and control coal and gas disasters. Reasonable extraction parameters can improve extraction efficiency and reduce the risk of gas accidents. In order to further study the influence of extraction parameters on gas drainage effect, this paper combines COMSOL Multiphysics numerical simulation and field experiment to optimize the two parameters of intubation spacing and extraction negative pressure in goaf of 42,201 working face in Buertai Coal Mine, Inner Mongolia. The three-dimensional gas distribution model in goaf was established, and the COMSOL numerical simulation software was used for calculation. Combined with the field experiment, the influence of intubation spacing and extraction negative pressure on the extraction effect was obtained. The results show that in the range of 50 m-70 m, the drainage effect is ideal when the negative pressure is 12–18 kPa. [ABSTRACT FROM AUTHOR]