Simulation Study on Parameters of “High-level Annular Body” for Surface Drilling and Drainage Face

• Published in: Mei kuang an quan Vol. 51; no. 12; pp. 40 - 44
• Main Author: GUO Zhongkai, HUANG He, YU Guofeng, CHEN Benliang, CHENG Haiyan, YU Yunfei
• Format: Journal Article
• Language: Chinese
• Published: Editorial Office of Safety in Coal Mines 01.12.2020
• Subjects: cosflow; gas drainage; high-level annular body; permeability; pressure relief; surface drilling
• ISSN: 1003-496X
• DOI: 10.13347/j.cnki.mkaq.2020.12.008

It can effectively improve gas drainage efficiency by arranging the surface drilling in the “high-level annular body” above the working surface. Based on the working condition of 17171(1) of Pansan Coal Mine, COSFLOW numerical simulation software was used to study and determine the range and location of the “high-level annular body” for gas drainage. The results show that: the height of the “high-level annular body” is within 108 m and 20 m above the mining coal seam. The front area adjacent to the working face is 140 m in advance direction of the working face. The outer boundary inclination angle extending to the roof is 70°, and the inner boundary inclination angle is 80°. During the recovery of 17171(1) working face, the average gas drainage flow volume of the surface drilling was 18.27 m3/min, which was 14.2% higher than the traditional method; the maximum value of the gas concentration for surface drilling drainage is 98% and the average is 50%, which meets the concentration requirements well for gas uti