不同矿物组分对泥页岩纳米孔隙发育影响因素研究

发布时间：2018-04-16 04:03

本文选题：页岩组分 + 等温吸附　；参考：《煤炭学报》2017年03期

【摘要】：选择四川盆地长宁双河镇上奥陶统五峰组—下志留统龙马溪组新鲜露头剖面样品,通过化学方法去除其中碳酸盐、硅酸盐及黄铁矿,利用低温二氧化碳和氮气吸附法对各处理阶段样品的纳米孔隙结构进行测定,通过等温线和NLDFT分析,对孔隙结构进行表征并分析不同矿物组分对原岩样品孔隙结构的影响。结果表明,对微孔部分而言,去除碳酸盐造成微孔体积减小,而去除硅酸盐和黄铁矿过程导致微孔体积增加,说明碳酸盐提供了页岩内部分微孔体积,可能来自于溶蚀孔的影响;对介孔-大孔部分而言,孔体积随着去矿物过程深入持续增加,说明矿物组分对这部分孔隙贡献较小。去矿物过程对样品不同尺度孔隙比例分布未产生明显影响,显示了介孔占据主要孔体积部分,微孔提供主要的表面积的特征。就孔径分布而言,微孔部分孔径分布受去矿物过程影响较大,而介孔-大孔部分孔径分布受去矿物过程影响较小。全岩样品微孔隙总体上体现了有机质孔隙发育特征,不同矿物组分在一定程度上由于和有机质处于包裹、填充、被填充的状态,对有机质原始孔隙信息,尤其是微孔部分起到更加明显的掩盖作用。总的来说,有机质是控制泥页岩微孔隙发育的最重要因素。
[Abstract]:The fresh outcrop section samples of upper Ordovician Wufeng formation and Lower Silurian Longmaxi formation in Shuanghe Town, Changning Basin, Sichuan Basin were selected to remove carbonate, silicate and pyrite by chemical method.The pore structure of samples was measured by low temperature carbon dioxide and nitrogen adsorption method. The pore structure was characterized by isotherm and NLDFT analysis and the effect of different mineral components on pore structure of original rock samples was analyzed.The results show that the removal of carbonate leads to the decrease of the micropore volume, while the removal of silicate and pyrite leads to the increase of the micropore volume, which indicates that the carbonate provides part of the micropore volume in the shale.For the mesoporous-macroporous part, the pore volume increases continuously with the process of mineral removal, which indicates that the mineral components contribute little to the pores in this part.The demineralization process has no obvious effect on the pore proportion distribution of the samples at different scales, showing that mesoporous occupies the main pore volume and micropores provide the main surface area.As far as pore size distribution is concerned, the partial pore size distribution of micropore is greatly affected by the process of mineral removal, while the distribution of mesoporous and macroporous partial pore size is less affected by the process of mineral removal.The micropores of whole rock samples generally reflect the characteristics of organic pore development, and the different mineral components are, to some extent, information about the original pores of organic matter due to the condition that they are wrapped, filled and filled with organic matter.In particular, the micropore part plays a more obvious role in masking.Generally speaking, organic matter is the most important factor controlling the development of shale micropores.
【作者单位】：中国科学院广州地球化学研究所;中国科学院有机地球化学国家重点实验室;中国科学院大学;
【基金】：中国科学院战略先导资助项目(XDB10010204)
【分类号】：P618.13

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