利用体积分方程的弱化BCGS算法模拟各向异性地层中多分量低频海洋可控源电磁响应  

Simulating multi-component low-frequency MCSEM responses in anisotropic formation using weak-form BCGS algorithm for volume integral equations

作　　者：魏宝君 刘莹 刘健 李静 陈涛 边旭 WEI Baojun;LIU Ying;LIU Jian;LI Jing;CHEN Tao;BIAN Xu(College of Science in China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)理学院,山东青岛266580

出　　处：《中国石油大学学报（自然科学版）》2023年第1期62-73,共12页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家重点研发计划项目(2019YFC1408104);中央高校基本科研业务费专项(20CX05013A)。

摘　　要：基于层状单轴各向异性介质的并矢Green函数和体积分方程的弱化稳定型双共轭梯度(BCGS)算法模拟各向异性背景地层中多分量低频海洋可控源电磁响应,并通过算例分析发射频率、海底背景地层各向异性和异常体埋藏深度对响应的影响特征。结果表明:发射信号的不同频率、电场强度的不同分量对海底油气藏的水平分辨能力不同;当测线沿x方向布设时,Ezz分量的分辨能力最强,Exx分量次之,Eyy分量的水平分辨能力最低;在海底背景地层水平电导率相同的情况下,背景地层垂向电导率的变化对Exx分量和Ezz分量的影响规律不同,而Eyy分量基本不受地层垂向电导率变化的影响;异常体埋藏深度越浅,Exx分量和Ezz分量对异常体的水平分辨能力越高,而无论异常体埋藏深浅Eyy分量均不能对其进行分辨。The multi-component low-frequency marine controlled-source electromagnetic(MCSEM) responses in anisotropic background formation were simulated based on dyadic Green? s functions for stratified uniaxial anisotropic medium and weak-form BCGS algorithm for volume integral equations. The influence of the transmitter frequency, anisotropy in the submarine background formation and the depth of the abnormal body were analyzed by numerical models. The results show that different frequencies of the transmitter and different components of the electric field have different horizontal resolutions for detecting the submarine oil reservoir. When the survey line is disposed alone x-direction, the resolving ability of the Ezz-component is most powerful, the Exx-component comes second, and the Eyy-component has lowest resolution ability. On the condition of the same horizontal conductivity of the submarine background formation, changes in the vertical conductivity of the background formation have different influences on Exx-component and Ezz-component, while the Eyy-component keeps unchanged. The horizontal resolving ability of Exx-component and Ezz-component become higher when the depth of the abnormal body becomes shallower, while the Eyy-component cannot resolve the abnormal body no matter whether the depth is shallow or deep.

关 键 词：体积分方程 海洋可控源电磁 各向异性 多分量 

分 类 号：P631.9[天文地球—地质矿产勘探]