Gas migration law of coal mining in seam with short distance to protection seam

In order to prevent mass gas in the protected seam rushing into the protective seam during the coal mining operation in the up- per protective seam with a short distance,a research was done on the law of gas distribution and gas migration after coal mining operations in the protective seam with a short distance to the next seam.The research results showed that the coal mining operations in the protective seam with a short distance to the next seam could let the protected seam fully release the pressure and effectively eliminate the outburst. There were over 85% of the total gas emission in the coal mining face of the protective seam coming from the pressure releasing and de- sorption gas of the protected seam.The gas were mainly accumulated at the upper corner and the adjacent certain space area and were con- tinuously discharged.When the absolute value of the gas content over the limits of 20 m3/min,the comprehensive gas control measures should be taken to ensure safety and high efficient production.