屯兰矿奥陶系隔水关键层孔隙性分析

以屯兰煤矿G3水文孔为取样孔,通过岩石薄片鉴定、X射线荧光光谱分析、岩石微结构分析等综合实验,分析了奥陶系峰峰组岩性、孔隙结构特征。研究表明:峰峰组上段为角砾状石灰岩;下段为泥晶白云岩,裂隙中充填粗粉晶石膏,岩溶不发育。峰峰组上段孔隙直径≥10μm的占27%,峰峰组下段中下部孔隙直径≥10μm的占11%,直径<0.1μm极细小和超毛管微孔隙占59%,说明峰峰组下段渗透性大大降低。峰峰组顶部和下部存在隔水层,可利用的隔水关键层厚度顶部35 m,下部70 m。

Porosity Analysis of Ordovician Water-resisting Key Strata in Tunlan Coal Mine

Taking G3 hydrological hole in Tunlan coal mine as sampling aperture and according to comprehensive experiments such as the rock slice appraisal,X-Ray fluorescence spectrum analysis and rock microstructure analysis,lithologic characters of Fengfeng Group and pore structure are analyzed.Research illustrate that the upper Fengfeng Group is breccia limestone,while the lower is dolomicrite filled with coarser crystal gypsum in fracture without karst development.The pore’s diameter≥10 μm in the upper Fengfeng group accounts for 27%,while that pore’s diameter in the middle and lower occupies 11% and the diameter <0.1μm of fine and supercapillary interstice takes up 59%,which means that the permeability of the lower Fengfeng group declines to a large extent.There is an aquifuge between the upper and lower Fengfeng group,in which the thickness of available water-resisting key strata is 35 m in the upper part and 70m in the lower.