A new parameter for characterizing pore-fracture structure heterogeneity:fractal dimension based on the mercury extrusion curve  

作　　者：Junjian ZHANG Anan XU Chengjin ZHAO Wei WANG Youlu JIANG Veerle VANDEGINSTE Zhengbao XUE Yuqiang GUO Heyao MIAO 

机构地区：[1]College of Earth Sciences&Engineering,Shandong University of Science and Technology,Qingdao 266590,China [2]School of Management,Changchun University,Changchun 130000,China [3]Geosteering&Logging Research Institute,Sinopec Matrix Corporation,Qingdao 266000,China [4]School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China [5]Exploration and Development Research Institute of PetroChina Southwest Oil&Gas Field Company,Chengdu 610041,China [6]Department of Materials Engineering,KU Leuven,Bruges,8200 Bruges,Belgium [7]The Second Exploration Team of Shandong Coalfield Geology Bureau,Jining 272000,China

出　　处：《Frontiers of Earth Science》2024年第4期782-796,共15页地球科学前沿(英文版)

基　　金：sponsored by the Research Fund of Shandong Coalfield Geological Bureau(No.2022-003).

摘　　要：Pressure mercury intrusion test is(MIP)one of the most commonly used methods to characterize pore-fracture structure.Here,we use the fractal dimension of the mercury intrusion curve to analyze the heterogeneity of pore and fracture distribution.Differing from the intrusive mercury curve,the extrusive curve provides a better representation of the seepage capacity of a reservoir.In this paper,the division method of sample types using both mercury invasive parameters(pore volume,pore volume percentage,porosity,permeability)and extrusive parameters(mercury removal efficiency)is discussed.The fractal dimension values of mercury intrusive and extrusive curves are calculated for all samples using the Menger,Thermodynamics,and Multifractal fractal models.Moreover,the fractal significance of the mercury withdrawal curve is examined.The results are as follows.1)The samples can be divided into three types based on the mercury removal efficiency and total pore volume.Type A is characterized by lower total pore volume(<0.08 cm3·g−1)and removal efficiency(<30%),type B has lower total pore volume(<0.08 cm3·g−1)and higher removal efficiency(>30%),and type C has larger total pore volume(>0.08 cm3·g−1)and higher removal efficiency(>30%).2)Mercury removal efficiency does not correlate with the mineral composition or total pore volume,but it does show a clear positive correlation with pore volume in the range of 100 to 1000 nm.Unlike the Menger model,the mercury removal curve analyzed using the thermodynamics and multifractal model shows good fractal characteristics.3)In contrast to the injective curves,the fractal dimension of mercury removal curves exhibits an obvious linear negative correlation with pore structure parameters and mercury removal efficiency.Moreover,the multifractal dimensions D0–D10 obtained from the mercury removal curves show a negative correlation with porosity and permeability.This indicates that fractal dimension based on the mercury extrusion curve can be used as a new parameter for characterizing

关 键 词：pore-fracture structure/mercury extrusion curve/pore structure/porosity/permeability 

分 类 号：O17[理学—数学]