中国石油大学学报（自然科学版）2018，Vol.42Issue(2)：19-28,10.DOI:10.3969/j.issn.1673-5005.2018.02.003
基于扫描电镜的页岩微观孔隙结构定量表征
Quantitative characterization of microscopic pore structure for shales using scanning electron microscopy
摘要
Abstract
The pore distribution of shales was extracted using the pores gray-level thresholds of the 2-dimensional high resolu-tion scanning electron microscopy (2D-SEM) images. The fractal dimension of pore morphology and radius were calculated using the fractal theory. The impacts of pore size distribution (PSD) model,radial step increase and resolution on the PSD determined by 2D-SEM were investigated,and the comparisons between the PSD determined by 2D-SEM,mercury intrusion capillary porosimetry (MICP),and low-temperature nitrogen adsorption/desorption(LNA/D) were made. The results show that the complexity of shale pore structure can be quantitatively characterized by the pore distribution extracted from 2D-SEM images. In general,the higher the fractal dimension of pore morphology is,the more complex the pores become;and a higher fractal dimension of pore radius usually results in a more complex PSD and a higher proportion of micropores. The PSD of shale can be precisely characterized by the continuous pore size distribution(C-PSD) method. The PSD determined from the 2D-SEM has a good consistency with that determined from the MICP and LNA/D,if the radial step increase is set to half of the average radius of pore throat. The PSD determined from the 2D-SEM is affected by the resolution and the heterogeneity of the pore distribution,so that the PSD should be determined from the high-resolution region representing the pore structure of shales (or the patchwork spliced by multiple high-resolution SEM images). The pore structure of shales can be precisely characterized by 2D-SEM images,providing a new method for investigating the pore structure of coring, and for shales that are difficult to prepare samples.关键词
扫描电镜/分形维数/孔径分布/孔隙结构/页岩Key words
scanning electron microscopy/fractal dimension/pore size distribution/pore structure/shale分类
能源科技引用本文复制引用
张鹏飞,卢双舫,李俊乾,薛海涛,李文镖,王思远..基于扫描电镜的页岩微观孔隙结构定量表征[J].中国石油大学学报（自然科学版）,2018,42(2):19-28,10.基金项目
国家自然基金重点基金项目(41330313) （41330313）
国家自然科学基金青年科学基金项目(41602131) （41602131）
中央高校基本科研业务费专项(17CX06036,17CX02074,YCX2017002) （17CX06036,17CX02074,YCX2017002）
中国石化股份有限公司资助项目(P17027-3) （P17027-3）
