Abstract
The coalbed methane (CBM) drainage effect of surface drainage after 5 years in Jincheng mining area was detected using the numerical simulation and measured method. The surface drainage effect of CBM detected by the measured method is adopted first time in China. It was measured that the CBM content by surface drainage after 5 years was declined from 21.58 m3/t to 10.47 m3/t, and the average value of reduced rate of gas content was 50.2%. After 15.6 months and 29.6 months by underground mine drainage it was measured that the CBM content was declined from 20.1m3/t to 11.24 m3/t and 4.76 m3/t respectively. According to the measured CBM content and the numerical simulation results of seam reservoir, combing with the practical experiences of CBM drainage in coal mine areas and the related management stipulations in China, and considering the safety of CBM drainage and the resource benefits in coal mine area comprehensively, it is suggested that the CBM content and the reduced rate (or recovery rate) of gas content are taken as the detection and evaluation indexes of CBM drainage effect in coal mine area, and the detection and evaluation technical methods of CBM drainage effect in coal mine area are established.
