An Innovative Drainage System for Coal Mine Methane Capture Optimisation and Abatement Maximisation

Gas drainage in Australian longwall mining is increasingly challenging because of complex gassy conditions, multi-seam environments, and environments where drilling a large number of conventional surface vertical gas drainage boreholes is not practical. This paper presents an alternative approach, using horizontal boreholes for longwall goaf gas drainage. This horizontal drainage method has been trialled successfully at the Blakefield South mine. The trial results show that horizontal drainage boreholes have significantly improved longwall gas management, through controlling goaf gas pressure distribution and flow pattern. As a result, gas related longwall production delays were largely eliminated and the fugitive emissions from the mine were significantly reduced.