摘要
考虑介质复杂的多尺度空间微结构相互作用的影响,地震波传播会出现明显的尺度效应.在广义连续介质力学理论框架下,组成介质的基本单元被建模为有体积属性的微元体,并将微元体之间长程力的作用纳入考虑,通过引入旋转/应变的高阶梯度以及表征介质空间微结构特性的尺度参数,可以在现有计算条件下,更好地表达地震波传播过程中的尺度效应.本文综合考虑偶应力效应和应变梯度效应对波传播的影响,介绍统一框架下的广义波动方程及其解耦表达,理论分析和数值实验结果表明,考虑介质复杂空间微结构相互作用的影响时,即使在各向同性均匀介质中,纵波和横波的传播均出现了频散现象,并且频散特征与尺度参数密切相关.此外,本文分析了尺度效应所导致的介质分界面处波形能量分配的变化,发现尺度效应的存在,会显著增强地震记录中与分界面相关的波场信息.本文研究可为储层的精细结构探测和物性信息解释,提供一种新的思路.
Considering the complex multi-scale microstructural interactions in the medium,observable scale effects emerge in seismic wave propagation.In the framework of the generalized continuum mechanics theory,the fundamental constituents of the medium are modeled as volumetric micro-elements,incorporating the effects of long-range forces between them.By introducing higher-order gradients of rotation/strain and scale parameters characterizing the spatial microstructure of the medium,the scale effects during seismic wave propagation can be better captured under current computational conditions.In this paper,the generalized wave equations and its decoupled expression are given under the unified framework with considering the influence of the couple stress effect and the strain gradient effect on wave propagation.Theoretical analysis and numerical experiments demonstrate that when accounting for the complex spatial microstructural interactions,even in an isotropic homogeneous medium,both P-wave and S-wave propagation exhibit dispersion,and the dispersive characteristics are closely related to scale parameters.In addition,the variation of wave energy distribution at the interface of the medium caused by scale effects is analyzed.It is found that the existence of the scale effect can enhance the wavefield information related to the interface in the seismic record,which can provide a new idea for the fine structure detection and physical property information interpretation of the reservoir.
作者
陈朝蒲
白文磊
刘洪
李幼铭
王之洋
CHEN ChaoPu;BAI WenLei;LIU Hong;LI YouMing;WANG ZhiYang(College of Information Science and Technology,Beijing University of Chemical Technology,Beijing 100029,China;Key Laboratory of Deep Petroleum Intelligent Exploration and Development,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《地球物理学报》
北大核心
2026年第3期1247-1261,共15页
Chinese Journal of Geophysics
基金
国家自然科学基金联合基金项目(U20B2014)
“HYXD”项目(XJZ2023050044,XJZ2023050052)共同资助.
关键词
广义波动方程
频散特征
尺度效应
数值模拟
Generalized wave equations
Dispersive characteristics
Scale effects
Numerical modeling
