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采用手标本观察、扫描电镜、压汞法、低温氮吸附和等温吸附试验等方法,综合分析了韩城矿区块构造煤储层煤体结构、孔隙系统、渗透性、甲烷吸附能力等物性差异特征。研究表明:构造运动引起煤岩宏观变形变质,碎裂煤、碎粒煤、鳞片煤、糜棱煤发育;微观-超微观视域内煤颗粒搬运、堆积,煤岩组分剪切变形、揉流褶皱,微米级范围内脆性、脆韧性、韧性煤层流变特征突出;构造变形程度增大,中孔比例升高,孔径配置由并联转化为串联,开放型孔逐步转化为细颈瓶型孔,渗流孔隙比例下降,吸附孔隙比例大幅升高,渗透性降低。但在富水文地质单元条件下,后生矿物充填易导致弱变形煤渗透率下降,加之裂隙由开启渐趋闭合,张性转换为压性、压剪性,孔隙系统及渗流特性的非均质性明显增强;弱变形碎裂煤比表面积至强变形糜棱煤差异量达7.476 3 m2/g,纳米级孔隙氮吸附量由0.698 2 mL/g增至9.354 3 mL/g,甲烷吸附能力显著提升。
The characteristics of physical properties such as coal body structure, pore system, permeability and methane adsorption capacity in the coal blocks of Hancheng mining block are analyzed synthetically by hand sample observation, scanning electron microscopy, mercury intrusion porosimetry, low temperature nitrogen adsorption and isothermal adsorption experiments . The results show that the tectonic movement caused macroscopic deformation and metamorphism of coal and rock, the development of fractured coal, crushed coal, flaky coal and mylonitized coal; the transportation and accumulation of coal particles in microscopic-ultramicroscope field, the shear deformation of coal and rock components, Fold, brittleness, brittleness and ductility, and ductile coal layer within the micrometer range. The degree of tectonic deformation is increased, the ratio of mesopores is increased, the aperture configuration is changed from parallel to series, and the open pore is gradually transformed into a flask- The proportion of seepage pores decreased, the proportion of adsorbed pores increased sharply, and the permeability decreased. However, under hydrofacies conditions, epigenetic mineral filling tends to lead to a decrease in permeability of weakly deformed coal, combined with a gradual closure of the fracture from opening to tension, compressive shear, pore system and anisotropy of seepage characteristics The difference between the specific surface area of weakly deformed fractured coal and strong deformed mylonitial coal is 7.476 3 m2 / g, the nitrogen adsorption capacity of nano-sized pores is increased from 0.698 2 mL / g to 9.354 3 mL / g, and the methane adsorption capacity is significantly increased .