학술논문
基于氮气吸附和压汞定量表征砂岩吸水孔隙结构演化规律 / Quantitative characterization of water absorption pore structure evolution in sandstone based on nitrogen adsorption and mercury intrusion
Document Type
Academic Journal
Author
孙晓明; 丁佳旭; 何林森; 石富坤; 缪澄宇; 张勇; 朱明群; 杨金坤; 谢铖; SUN Xiao-ming; DING Jia-xu; HE Lin-sen; SHI Fun-kun; MIAO Cheng-yu; ZHANG Yong; ZHU Ming-qun; YANG Jin-kun; XIE Cheng
Source
中南大学学报（英文版） / Journal of Central South University. 31(1):182-195
Subject
Language
Chinese
ISSN
2095-2899
Abstract
为了探究水对岩石孔隙结构的作用机制,本文依托山东万福煤矿砂岩地层,针对不同浸泡时间作用下的砂岩试样,开展扫描电镜、氮气吸脱附和高压压汞联合孔隙结构测试实验,分析微孔(<2 nm)、介孔(2～50 nm)和大孔(>50 nm)的孔隙结构变化规律.结果表明:砂岩孔隙结构类型为狭窄型和楔形结构,孔隙之间具有连通成缝的能力.砂岩吸水过程中孔隙度先减少后增加.微孔占比先减少后增加,介孔和大孔占比先增加后减少.根据广义分形维数和谱宽定量评估孔隙结构,得出其与孔隙质量正相关,即分维差值和谱宽越大,孔隙结构越复杂;而与岩石孔隙度呈负相关,即较大孔隙度对应较小的分维数差值和谱宽.
To investigate the mechanism of water's effect on the pore structure of rocks,this study relies on the sandstone formation in Wanfu Coal Mine,Shandong,China.Scanning electron microscopy(SEM),nitrogen adsorption-desorption,and high-pressure mercury intrusion combined with pore structure testing experiments were conducted on sandstone samples subjected to different immersion times.The aim was to analyze the variations in the pore structure of micropores(<2 nm),mesopores(2-50 nm),and macropores(>50 nm).The results indicate that the pore structure of the sandstone consists mainly of narrow and wedge-shaped structures.The pores have the ability to connect and form fissures.During the water absorption process,the porosity of the sandstone initially decreases and then increases.The proportion of micropores decreases initially and then increases,while the proportion of mesopores and macropores increases initially and then decreases.According to the quantitative assessment of pore structure using generalized fractal dimension and spectral width,it is found that there is a positive correlation between pore structure and pore quality.That is,as the difference in fractal dimension and spectral width increases,the pore structure becomes more complex.There is a negative correlation between pore structure and porosity,that is,larger porosity corresponds to smaller differences in fractal dimension and spectral width.
To investigate the mechanism of water's effect on the pore structure of rocks,this study relies on the sandstone formation in Wanfu Coal Mine,Shandong,China.Scanning electron microscopy(SEM),nitrogen adsorption-desorption,and high-pressure mercury intrusion combined with pore structure testing experiments were conducted on sandstone samples subjected to different immersion times.The aim was to analyze the variations in the pore structure of micropores(<2 nm),mesopores(2-50 nm),and macropores(>50 nm).The results indicate that the pore structure of the sandstone consists mainly of narrow and wedge-shaped structures.The pores have the ability to connect and form fissures.During the water absorption process,the porosity of the sandstone initially decreases and then increases.The proportion of micropores decreases initially and then increases,while the proportion of mesopores and macropores increases initially and then decreases.According to the quantitative assessment of pore structure using generalized fractal dimension and spectral width,it is found that there is a positive correlation between pore structure and pore quality.That is,as the difference in fractal dimension and spectral width increases,the pore structure becomes more complex.There is a negative correlation between pore structure and porosity,that is,larger porosity corresponds to smaller differences in fractal dimension and spectral width.