Author(s): Li Yongjun, Shi Yanqiang, Shi Weijie, Yang Lifang
Pages: 24-31,45
Year: 2013 Issue:  8
Journal: Coal Geology of China
Keyword:  lower group coal seams; gas hosting condition; coal reservoir features; gas outburst index; Xingwu and Jinjiazhuang coalmines;
Abstract: Through analyses of gas hosting condition and coal reservoir features in the Xingwu and Jinjiazhuang coalmines, integrated regional data and mining situation of upper group coal seams, preliminarily assessed gas outburst hazard of lower group coal seams. The CH4 content in lower group coals is 0.05~4.63ml/g, average 1.48ml/g, concentration of CH4 1.42%~96.63%, CO20.51%~64.01%, N2 0.08%~68.20%, as a whole, CH4content is higher in the deep part;the coal Protodyakonov coefficients are all larger than 0.3, gas pres-sures all less than 0.74MPa, other indices partly at the critical value range, but the comprehensive assessment of lower group coal seams gas outburst overall index does not exceed the standard, thus small outburst hazard.