Integrated coal and gas extraction in mining the first seam with a high cutting height in multiple gassy seams of short intervals
Abstract：There are a number of challenging technical issues in mining the first seam with a high cutting single pass longwall method in thick and multiple gassy seams of short intervals in the western region of China.These issues include the stability of retained gateroads and the quantification of the extent and degree of destressed zones in surrounding strata.To gain an insight of these issues,a theoretical and numerical study was undertaken for a 4.2 m cutting height face to understand the propagation and evolution of fractures around the face,to characterize the fracture distribution,and to map out the zones of high gas concentrations in the goaf.Based on these findings,a group of large diameter(φ=250 mm) boreholes drilled into the zones,instead of conventionally expensive gas drainage tunnels,are successfully used to capture the goaf gas.A total of 11.669 5 million cubic meters gas is captured with the boreholes,a total of 677 000 tons of coal is efficiently extracted without any gas issue,and integrated coal and gas extraction is achieved.
Keywords：simultaneous extraction of coal and gashigh gasshort-distance coal seams grouplarge mining heightroof cracks development lawlarge diameter boreholes group
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 1682-1687 )