Optimization and application of key parameters of gas extraction in soft and low permeability coal seam
Guo Xiaoxing 1, Su Guoqing 1, Zhu Rui 2
1. Shanxi Lu 'an Mining Group Cilinshan Coal Industry Co., Ltd. Licun Coal Mine, Changzhi 046600, China; 2. School of Mining, Liaoning Technical University, Fuxin 123000, China
Based on the research background of 3302 working face in Licun Coal Mine, this paper focuses on the key problem of limited gas extraction efficiency in soft and low permeability coal seam. By constructing a fluid-solid coupling model, combined with numerical simulation and field application, the key parameters of gas extraction were optimized in depth. With the help of COMSOL-Multiphysics simulation software, the gas extraction effects of single-row holes and three-flower holes were simulated and analyzed, and then the reasonable hole arrangement and spacing were determined, and the optimized parameters were applied to the field practice of Licun Coal Mine. The results show that the single-row holes have better gas control effect at both ends of the coal body, while the three-flower holes have better overall gas extraction effect, but the gas control effect at the far corner points at both ends of the model is not good. The scheme of single row of holes and drilling spacing of 2.0 m can reduce the gas pressure by more than 30%, which meets the engineering requirements. This study provides an effective reference for gas extraction in similar soft and low permeability coal seams.