煤田地质与勘探2017，Vol.45Issue(5)：41-47,7.DOI:10.3969/j.issn.1001-1986.2017.05.008
陆相页岩热演化过程中孔隙分形特征
Fractal characteristics of pore structure of continental shale in the process of thermal evolution
摘要
Abstract
Fractal dimension can characterize quantitatively the complexity of pore structure of a reservoir and provides ideas for evaluation of shale reservoir.With the shale Chang 7 of Yanchang Formation in Ordos basin as the object,field emission scanning electronic microscope was used to observe the pore characteristics of thermal evolution stages,through the low temperature nitrogen adsorption experiment,the fractal characters of shale pore structure of different evolutionary stages were studied.FHH model was applied to calculate the pore fractal dimension.The relationships between the fractal dimensions and composition,the pore structure parameters were investigated.The results show it had not reached gas window for remaining a low thermal evolution stage for the primary sample,immature source rocks had not begun to generate a lot of hydrocarbons.With thermal maturity increasing,pores began to form gradually in the organic matter,especially,interlayer nanopores generated for the decomposition of organic matter within the clay.There existed mainly ink bottle-like pores and a few of parallel tabular pores,peak pore diameter was in 2～4 nm and 40～50 nm.With increase of maturity,the relative quantity of pores in the two above ranges of pore diameter increased,fractal dimension increased successively,the fractal dimension was 2.592～2.717.The fractal dimensions were negatively correlated with TOC,but show no obvious relationship with the quartz and clay mineral content,the proportion of micropores and mesopores increased with thermal maturity,the average diameters decreased,pore surface was more complicated,the specific surface and fractal dimensions increased.The relationship between total pore volume,micropore volume,mesopore volume and fractal dimensions were positively correlated,while macropore volume and fractal dimensions were poorly correlated.The fractal dimension could be used to evaluate the complexity of reservoir,it provides support for shale reservoir evaluation and adsorption.关键词
鄂尔多斯盆地/陆相页岩/热演化/低温液氮吸附/分形特征Key words
Ordos basin/continental shale/thermal evolution/nitrogen adsorption/pore structure/fractal characteristics分类
天文与地球科学引用本文复制引用
马明,陈国俊,徐勇,胡士骏,吕成福,薛莲花..陆相页岩热演化过程中孔隙分形特征[J].煤田地质与勘探,2017,45(5):41-47,7.基金项目
国家自然科学基金项目(41272144,41402130) （41272144,41402130）
中国科学院战略性先导科技专项(B类)(XDB10010300) National Natural Science Foundation of China(41272144,41402130) （B类）
The Strategic Leading Science and Technology(B)of Chinese Academy of Sciences(XDB10010300) （B）
