石星辰^1,2,,
毛伟建^1,,,
栗学磊¹
1. 中国科学院测量与地球物理研究所计算与勘探地球物理研究中心, 大地测量与地球动力学国家重点实验室, 武汉 430077
2. 中国科学院大学, 北京 100049

基金项目: 国家重点研发计划项目（2018YFC0310104），国家自然科学基金重点项目（U1562216）和国家科技重大专项项目《新一代地球物理油气勘探软件系统》（2017ZX05018-001）联合资助


详细信息

作者简介: 石星辰, 男, 1992年生, 在读博士, 主要从事多波多分量偏移成像方法研究.E-mail:shixingchen@asch.whigg.ac.cn

通讯作者: 毛伟建, 男, 研究员, 博士生导师, 主要从事地震数据处理、成像和反演研究.E-mail:wjmao@asch.whigg.ac.cn

中图分类号: P631

收稿日期:2018-01-02
修回日期:2018-11-21
上线日期:2019-04-05

Viscoelastic Q-compensated Gaussian beam migration based on vector-wave imaging

SHI XingChen^1,2,,
MAO WeiJian^1,,,
LI XueLei¹
1. Chinese Academy of Sciences, Institute of Geodesy and Geophysics, Center for Computational and Exploration Geophysics; and State Key Laboratory of Geodesy and Earth's Dynamics, Wuhan 430077, China
2. University of Chinese Academy of Sciences, Beijing 100049, China


More Information

Corresponding author: MAO WeiJian,E-mail:wjmao@asch.whigg.ac.cn

MSC: P631

--> Received Date: 02 January 2018
Revised Date: 21 November 2018
Available Online: 05 April 2019


摘要
摘要:基于弹性波动理论的多波多分量高斯束偏移具有计算效率高和成像准确等优点.但是目前此方法没有考虑实际地下介质的黏弹性对地震波传播的影响，从而无法补偿能量衰减和校正相位畸变，这使得该方法对一些含高黏弹性地层的成像效果不佳.针对衰减区域的成像问题，本文提出一种黏弹性衰减补偿高斯束偏移方法，该方法以多波多分量矢量波场弹性高斯束偏移方法为基础，在偏移过程中沿射线路径通过引入品质因子Q来考虑黏弹性影响并进行衰减补偿.该方法能够在偏移过程中实现PP波和PS波的自动分离及分别成像.同时，本文给出了在矢量波场偏移过程中提取角度域共成像点道集的方法，以便用于成像质量控制，并为后续速度和黏弹性参数反演提供所需的数据.本文利用2D层状模型和洼陷模型进行了方法测试，其成像结果验证了本文所提出的黏弹性衰减补偿高斯束偏移方法的可行性和有效性.
关键词: 黏弹性高斯束/
偏移/
多波多分量/
矢量波场成像

Abstract:Elastic-wave equation based multicomponent Gaussian beam migration is a desirable method for its efficiency and accuracy. However, it is not applicable for attenuating media in which anelasticity of the subsurface will cause amplitude loss and phase distortion of seismic waves. Meanwhile seismic attenuation will lead to poor illumination and misplacement of reflectors in a migration image. To increase the resolution of seismic migration images, it makes sense to compensate for such attenuation effect. To process multicomponent seismic records in a viscoelastic medium correctly, we propose a vector-based Gaussian beam migration method with attenuation compensation. In this approach, viscoelasticity is taken into consideration by introducing the quality factor (Q). Attenuation is compensated along seismic rays. We correct the travel time with Q and extend the Gaussian beam migration from elastic media imaging to viscoelastic attenuation compensation imaging. Multimode and multicomponent waves are automatically decomposed into PP and PS waves during the migration without prior separation. In order to monitor imaging quality, angle-domain common image gathers are acquired during the vector-based migration, which can be utilized for migration velocity analysis and amplitude-variation-with-angle (AVA) inversion. Numerical experiments demonstrate that this method is feasible and efficient.
Key words:Viscoelastic Gaussian beam/
Migration/
Multi-mode multi-component/
Imaging of vector-wave field



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