Study On The Characteristics Of Gas Content And Emission Based On The Information Of Drilling

Gas disaster is one of the most severe geological disasters in mining safety. On the other hand, gas is a kind of precious clean energy, experts believe gas will become China's new energy. Researching on the characteristics of occurrence and migration of gas, it will be a signification at calculation of gas resources, prediction of gas emission, gas-geology evaluation and development of gas and geology theories, gas control and utilization. Based on the principle of coal seam gas occurrence and migration conditions are controlled by country rock structure, the control action of coal seam gas occurrence and migration by country rock structure was evaluated in this paper, using core recovery and flush fluid loss, and it had a new light of the calculation of gas resources.Through compiling and regression analyzing gas data and data of 68 drills of seven coal seams in Qidong, Qinan, Wolonghu and Taoyuan mine fields, it showed that:(1)There is a parabolic relationship between gas content and core recovery, and the mash gas content increased taken with the core recovery, but the range of increase is decreasing; When the core recovery closed to 100 percent, coal gas content tended to a constant, this constant is related to the volume of gas that generated in metamorphism stage.(2)There is linear relationship between flush fluid loss per meter and gas content; and the gas content decrease when flush fluid loss increase, it shows a negative relation.(3)There is a polynomial relationship among the gas content, core recovery and flush fluid loss per meter in Qidong mine field.(4)According to the analysis of core recovery, there is an obvious characteristic of No.10 coal seam in north six mining area in Taoyuan mine field. It can be divided into three regions, the roof is fragmentized and core recovery is lower in centre portion, and the roof is integrated and the core recovery is higher in both shallow and deep portion. It has a polynomial relationship between absolute volume of gas emission of north eight roadway and core recovery in north six mining area in Taoyuan mine field, with negative relation. The abnormal gas emission of north eight roadway in north six mining area in Taoyuan mine field. It is because the gas migrated and enriched in the adjacent rock of the roof of No.10 coal seam in geological process, and gave out to the roadway space when tunneling.(5) The gas resources of one coal seam in normal area is equate to the product of gas content of the coal seam when the core recovery is 100 percent and the geological reserves of coal seam, and the total gas resources in this area are equate to the sum of all the coal seams' gas resources in this area.