松软低渗区不同煤体结构煤的孔裂隙发育特征

Pore and Fissure Development Characteristics of Coal with Different Coal Structure in Soft and Low Permeability Area

为考察赵庄矿松软低渗区不同煤体结构煤的孔裂隙微观特征,基于井下煤壁、取芯井观测、液氮吸附、扫描电镜等方法,开展煤体结构特征及孔裂隙发育状态研究。结果表明:受构造作用影响,3#煤层上下部存在“软硬”分层现象;随着构造破坏程度的增高,煤的孔容、比表面积、平均孔径均逐渐增大,原生结构煤、碎裂结构煤、碎粒结构-糜棱结构煤样分别以Ⅰ类、Ⅱ类、Ⅲ类孔隙存在,扫描电镜下煤体的完整性和连通性逐渐变低,渗透性能整体较差。

In order to investigate the micro characteristics of pores and fissures of different coal structures in the soft and low permeability area of Zhaozhuang mine,the coal structure characteristics and pore and fissure development state were studied based on underground coal wall,coring well observation,liquid nitrogen adsorption and scanning electron microscope.The results show that"soft and hard"stratification exists in the upper and lower parts of No.3 coal seam under the influence of tectonism;with the increase of the degree of structural damage,the pore volume,specific surface area and average pore diameter of coal gradually increase.The primary structure coal,cataclastic structure coal and broken grain structure mylonite structure coal samples exist in classⅠ,classⅡand classⅢpores respectively.Under the scanning electron microscope,the integrity and connectivity of the coal body gradually decrease,and the overall permeability is poor.