文献类型：期刊文献

英文题名：Fractal analysis of CT images of tight sandstone with anisotropy and permeability prediction

作者：Yang, Yu[1];Wang, Dong[2];Yang, Jingyi[3];Wang, Bin[2];Liu, Tao[1]

机构：[1]East China Univ Sci & Technol, Shanghai Key Lab Multiphase Mat Chem Engn, Sch Chem Engn, Shanghai 200237, Peoples R China;[2]Zhongyuan Oilfield Branch Co, Petr Engn Inst, SINOPEC, Puyang 457001, Peoples R China;[3]East China Univ Sci & Technol, Int Joint Res Ctr Green Energy Chem Engn, Sch Chem Engn, Shanghai 200237, Peoples R China

年份：2021

卷号：205

外文期刊名：JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING

收录：;EI(收录号：20212310470348);WOS:【SCI-EXPANDED(收录号:WOS:000669473000001)】；

基金：The authors are grateful to the National Natural Science Foundation of China (21676081) . Prof. Zhou W.X., East China University of Science and Technology, is thanked for having a useful discussion with us on the manuscript.

语种：英文

外文关键词：Digital rock analysis; Fractal geometry; Heterogeneous porous media; Permeability

摘要：For developing unconventional oil and gas resources, it is necessary to quantify the heterogeneity embodied in both pore-size distribution (PSD) and pore spatial distribution, on the basis of which the relationship between the seepage characteristics and the microstructure of heterogeneous porous media could then be clarified. In this work, micro computed tomography (mu CT) and image processing technology were applied to characterise matrix pore structure in tight sandstone. Fractal theory was used to investigate the image-based heterogeneity of tight porous media. On the basis of the verification that the PSD of the tight rock is statistically self-similar at a certain scale, we investigated the relationships between porosity and fractal dimension, and between 2D and 3D fractal dimensions, respectively. The results showed that the pore structure characteristic parameters with anisotropy, i. e., the ratio of the minimum pore size to the maximum pore size lambda max/lambda min and a proportionality constant CKT, could be obtained by liner fitting fractal dimension and porosity. Moreover, the 2D PSD characteristics of the 'standard cross section' were consistent with the 3D PSD characteristics of pore network. A fractal permeability model was established by treating the connected pores in the matrix as a bundle of conical micropipes. The permeability values predicted by the proposed model agreed well with those predicted by finite volume method simulation under the condition where irreducible pores were removed. A sensitivity analysis indicated that increasing the heterogeneity of the PSD and pore spatial distribution reduced the flow capacity of the matrix, particularly for low-porosity porous media.