极薄煤层钻采上覆煤层卸压变形及渗透性演化规律

Pressure Relief Deformation of the Upper Coal Seam and Evolution Laws of Permeability When Drilling Thin Coal Seam

通过相似材料试验及现场工程测试等手段,对极薄近距离下保护层钻采上覆被保护层垂直应力、膨胀变形、渗透率演化规律进行了研究,得出了钻采极薄下保护层上覆被保护层的垂直应力、膨胀变形及渗透率变化规律等。研究结果表明,钻采极薄近距离下保护层二1煤垂直应力降低60%以上,相对膨胀变形率12‰,相似材料体渗透率增大15倍。钻采一9煤对上覆二1煤能形成保护效果,引起了二1煤卸压增透、卸压增流效应,降低了二1瓦斯抽采难度,消除了二1煤的突出危险性,研究成果可推广应用于极薄保层开采。

Conducting a study for the vertical stress,expansion deformation and evolution laws of permeability of drilling the upper protected seam under the thin protective seam close by similar materials testing and field engineering test.The results showed that vertical stress of drilling under the thin protective seam close 21 coal reduced more than 60%,relative expansion of deformation rate was 12‰,body permeability of similar material was 15 times larger.drilling 19 coal made a protective effect for the upper 21 coal,which caused a effect of pressure relief for increasing the gas permeability and flow of 21 coal,reduced the difficulty of the 21 gas extraction,eliminated the outburst risk of 21 coal.The study results can be spread and applied to thin protective seam mining.