A critical analysis of gas data in relation to gas drainability in the Bulli seam

摘要: To prevent the outburst fatality, threshold limits was established. It is stipulation of on seam gas content prior to mining. The varied linearly based composition, increasing from a minimum in CO2 rich conditions maximum CH4 conditions. believed that data drainage boreholes are closely related drainability Bulli Seam. A total 519 sample results Metropolitan mine has been examined. found Q1, Q2 and Q3 components increased response measured QM. Statistical analysis also shows an trend Q1:QM Q2:QM ratio corresponding QM, but there decrease Q3:QM power relationship considered more accurately represent average each component relative especially for “Fail” samples. value composition “Pass” samples 73.5 % it 82.6 zone with CH4/ (CH4+CO2) less than 0.2 includes 171 samples, accounting 88.1