Three region linkage comprehensive gas control model based on ground and underground gas joint drainage

In order to solve the problems of gas outburst and coal and gas outburst in the process of mining close coal seams with outburst risk,through establishing a space-time coordinate system for gas prevention and systematic analyzing the temporal and spatial distribution of ground and underground gas drainage technology and its constraint condition,then temporal and spatial conversion mechanism of ground and underground combined drainage in coal mining three districts was revealed.Based on close-distance multi-seams mining characters in Shaqu coal mine,three types of ground wells were widely used in the planning area to achieve large-scale CBM pre-drainage,directional docking drainage technology of Multi-branch horizontal wells and kilometer drilling-holes,and large-aperture directional long drilling-holes drainage technology were implemented firstly in development and production districts.With ground and underground drainage methods’ optimizing and integrating,combined CBM utilization technology,comprehensive gas control mode and its supporting technology system of Shaqu coal mine were formed.After practice engineering verification,the implementation of “Shaqu mode” could realize zero over-limitation of gas in work faces,basically eliminate the outburst danger of coal seams,which ensure the safe and efficient production of mines,and its application with CBM comprehensive utilization to generate significant economic and social benefits.