极近距离煤层与油页岩复合顶板裂隙发育及瓦斯涌出规律研究

Research on the crack development and gas emission law of the composite roof between coal seam and oil shale in very close distance

为研究含极近距离煤层和油页岩复合顶板的低瓦斯矿井瓦斯涌出异常原因,采用理论分析、数值模拟、实验室实验及现场实测等手段进行了相关研究。研究认为:贯屯煤矿开采5号煤层时,裂隙带最大范围为21 m左右,煤层上方6号煤层与油页岩均位于冒落带和裂隙带内;贯屯煤矿5号、6号煤层及油页岩瓦斯含量分别为2.71、2.40、0.09 m^(3)/t,50109综采面、50212综采面绝对瓦斯涌出量分别为3.67、3.02 m^(3)/min;综采面上方极近距离煤层、油页岩复合顶板厚度和上隅角瓦斯涌出异常程度呈正相关;建议上隅角瓦斯治理采取高位钻孔抽采和采空区埋管抽采。研究成果对陕北三叠纪含油页岩煤田瓦斯治理具有指导意义。

to study the causes of abnormal gas emission in low-gas mines with extremely close coal seams and oil shale composite roofs,relevant researches had been carried out by means of theoretical analysis,numerical simulation,laboratory experiments and field measurements.According to the research,when the No.5 coal seam was mined in the Guantun coal mine,the maximum range of the fissure zone was about 21 m,and the No.6 coal seam and the oil shale above the coal seam were located in the caving zone and the fissure zone;the No.5 and No.6 coal seams and the gas content of oil shale was 2.71,2.40,0.09 m^(3)/t,the absolute gas emission of 50109 fully-mechanized face and 50212 fully-mechanized face were 3.67,3.02 m^(3)/min;the distance above the fully-mechanized face was very close,the thickness of the composite roof of coal seams and oil shale was positively correlated with the abnormal degree of gas emission in the upper corner;it was recommended that the upper corner gas control should adopt high-position drilling and drainage with buried pipes in the goaf.The research results had guiding significance for gas control in Triassic oil-bearing shale coalfields in Northern Shaanxi.