Saint-Petersburg Mining University, Saint-Petersburg, Russia

The article addresses the issue of the enhancement of efficiency in pre-mining drainage of unloaded coal bed methane with a view to improving the coal mine safety and increasing the face output. The coal mining industry in Russia is one of the backbones of the national economy. A distinctive feature of mining to date is deterioration of operating conditions: deep level of mining, increased gas content of coal beds, as well as increased gas inflow from enclosing rocks and growth of outburst hazard with the depth of coal mining. Majority of fatal large accidents in mines were caused by methane explosions due to high methane content of coal beds under mining and owing to erratic ventilation of roadways. High explosibility of air and methane mixture makes coalbed methane one of the key hazards for mining and a constraint for using modern high-production equipment. Enhancement of mining efficiency is possible through introduction of new technologies based on the estimation of the entire production chain and on the implementation of measures aimed at improvement of mine performance and personnel training quality. The article describes the method of an unloaded coal bed treatment by hydraulic perturbation created at the mouth of a hole drilled from a gateway. Such treatment increases gas permeability of coal. The pulsed hydrodynamic impact is exerted on the unloaded coal bed in the course of coalbed drainage. The authors analyze the results of the experiment carried out in Boldyrevsky coal bed in Kirov Mine (Leninsk-Kuznetsky, Russia). The goal of the analysis is to improve coalbed drainage efficiency by means of selecting proper parameters of the hydraulic pulsed treatment.