Study on direct measuring method of seam gas drainage radius in underground mine-establishment and application of Gas Reserves Method

According to a problem of no unified standard to the radius measured method of the seam gas drainage in China coal underground mine, the paper had a summarization and review on the related study on the available gas drainage radius and had an analysis and discussion on the gas drainage definition, the defined index and measured method. The paper had a classification and comparison on the direction measured method of the seam gas drainage radius. Gas Reserves Method of the gas drainage radius direct measured in the underground coal mine was established and was applied to the site application practices. The study results showed that the defined index of the gas drainage radius should be scientifically set up according to the gas drainage purpose of the certain mine. The direct measured method of the available gas drainage radius could divide the gas pressure reduction method, the gas content reduction method, the gas drainage flow method and the gas tracer method. Based on the improvement of the gas drainage flow method, the Gas Reserves Method provided could actually reflect the mine gas drainage status. The requirements of the site test condition would be simple. The Gas Reserves Method would have high suitability,a reliable test result and could be a reliable direct measured method of the gas drainage radius in the underground mine to be promoted and applied.