CHINA MINE ENGINEERING

The essay is a case study of 3109 haulage roadway development. To improve gas control efficiency, antireflection was conducted by applying directed hydraulic fracturing at the coal body in front of the workface. After theoretical analyses, project comparison and studying site gas control actualities, a directed hydraulic fracturing antireflection scheme was developed and practiced. Finally a remarkable success was achieved: gas extraction drilling purity and concentration were improved by 30% and 150%, and gas control time was reduced by about 1/3.