基于过程法研究虚拟岩心结构参数对低频激发极化效应的影响  

Study on the influence of structural parameters of virtual core on low-frequency induced polarization using process-based method

作　　者：马铭[1] 赵建国[1] 毛玉蓉[2] 闫博鸿 叶麦克 肖增佳 李智[1] 王斌[1] MA Ming;ZHAO JianGuo;MAO YuRong;YAN BoHong;YE MaiKe;XIAO ZengJia;LI Zhi;WANG Bin(State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,Wuhan 430100,China)

机构地区：[1]中国石油大学(北京)油气资源与工程全国重点实验室,北京102249 [2]长江大学油气资源与勘探技术教育部重点实验室,武汉430100

出　　处：《地球物理学报》2025年第3期1148-1162,共15页Chinese Journal of Geophysics

基　　金：国家自然科学基金联合基金重点项目(U20B2015);国家自然科学基金项目(41974120)联合资助.

摘　　要：不含金属矿物的多孔介质低频激发极化效应与结构参数密切相关,为了明确结构参数对激发极化效应的影响,本文结合过程法和复电导率数值模拟技术进行分析.首先,基于过程法的成岩和压实过程重构了不同结构参数的虚拟岩心;然后,分析了粒径和压实系数变化对结构参数的影响;之后,提出将压实过程等效为颗粒体积膨胀过程,并引入等效粒径来表征压实系数;最后,将双电层贡献的表面复电导平均在颗粒体积上,进而在代表性体积单元中求解电场拉普拉斯方程获得多孔介质的等效复电导率.结果表明:压实系数在[0.14,0.22]之间变化时,结构参数将受到显著影响;电化学极化弛豫峰对应的相位值与单位孔隙表面积比体积正相关;随着压实系数的增加,电化学极化和Maxwell-Wagner极化都将增强,且两种极化过程之间或出现第二个特征弛豫峰;此外,正交电导率与结构参数之间的变化规律不是单调的.该研究将为从激发极化测量结果预测多孔介质的结构参数提供依据.The low-frequency induced polarization effect in porous media without metal minerals is closely related to structural parameters.To elucidate the impact of these structural parameters on the induced polarization effect,this study employs a combination of process-based methods and numerical simulation techniques for complex conductivity.Firstly,virtual cores with varying structural parameters are reconstructed based on the sedimentation and compaction processes of the process-based method.Then,the effects of variations in particle size and compaction coefficients on structural parameters are analyzed.Subsequently,it is proposed to equate the compaction process to a particle volume expansion process and to introduce an equivalent particle radius to characterize the compaction coefficient.Finally,the surface complex conductivity contributed by the electrical double layer(EDL)is averaged over the particle volume,and the equivalent complex conductivity of the porous media is obtained by solving the electric field Laplace equation in a representative volume element.The results indicate that when the compaction coefficient varies between[0.14,0.22],the structural parameters are significantly affected.The phase corresponding to the relaxation peak of electrochemical polarization is positively correlated with the specific surface per unit pore volume.As the compaction coefficient increases,both electrochemical polarization and Maxwell-Wagner polarization also increase,and a second characteristic relaxation peak may appear between the two polarization processes.Furthermore,the relationship between quadrature conductivity and structural parameters is not monotonic.This study will provide the potential to predict the structural parameters of porous media based on induced polarization measurements.

关 键 词：过程法 压实系数 等效粒径 结构参数 复电导率 激发极化 

分 类 号：P631[天文地球—地质矿产勘探]