ABSTRACT
Gas drainage is an effective measure for gas and ventilation management in underground coal mines. Each year, tens of thousands of meters of drainage holes drilled do not produce the volume expected because some of them are targeted at area of low gas content. This paper presents some findings of gas production associated with mining activities and understandings how to effectively design underground gas drainage holes. As part of the project, sites at two underground coal mines were selected to conduct field investigations using specially developed equipment. Gas drainage holes, including cross-panel and cross-measure holes, for three longwall panels, were monitored during longwall extraction. Another part of the project was to validate gas content at various stages by drilling additional in-seam and cross-seam holes in selected areas.
