Study On Gas-geology Law And Gas Control Technique Zhang Wei Coal Mine

In recent years, as the mine mining depth increasing, the gas problem increasingly prominent. No.C16 coal seam is the main seam of Zhangwei coal mine.Coal seam gas content and coal and gas outburst range are increasing with the depth of coal seam mining, becoming a serious threat to the safety of mine. Therefore researching the law of gas geology and analyzing factors of buried depth and rock thickness which influence the balance gas distribution, is the urgent problems on the mine currently production work.Firstly, based on analysis of geological structure theory and gas occurrence and control tectonic theory, this paper made the conclusion of that Zhina coalfield was mainly affected by sharp tectonic movement of uplift of Central Guizhou and it’s adjacent areas. A regional faults named Zunyi fault which accompanied by a series of NS trending folds and faults has formed at the eastern boundary of the coalfield. The strong extrusion from east to west make the fault zone of Yadu-Ziyun occur compressing and shearing activity and a series of NW trending folds and faults formed. All of those make Zhina coalfield which have complex structure, tectonic stress concentration become coal and gas outburst area.Secondly, according to the actual occurrence of gas, and combined with the data of gas content and gas pressure which measured in the present of Zhangwei coal mine,and based on analyzing the influence of various factors on the gas content of coal seam, the logarithmic relationship between gas content and buried depth have been established. The results show that: Burial depth of coal seam is the main factor controlling the distribution of gas content and gas content increases with the depth of coal seam. According to the measurement and monitoring gas emission data of the mine, useing the partial source prediction method to predict the gas emission and find that predicted gas emission is comparable to measured gas emission.Thirdly, according to the mechanism of coal and gas outburst and combining with the results of gas content prediction, this paper use the gas pressure parameters to predict regional outburst hazard. When the buried depth is 140 m, the gas pressure approach to 0.74 MPa. And when the buried depth is 125 m, the gas content is 8m3/t.Therefore, the area of the No.C16 coal seam which below the 125 m buried depth is dangerous area of coal and gas outburst.Finally, according to the divided outburst area, the regional and local outburst prevention measures were mainly taken combining with the practical situation of the mine.