报告地点：腾讯会议(会议ID：411 4788 6096）
报告时间：2020-11-20 从 15:00 到 16:30
报告人：赵杨
报告人简介：
赵杨, 国家特聘青年专家，中国石油大学(北京) 教授，博士生导师，硕士生导师； 2006年北京大学本科毕业赴美，2013年初于美国加州伯克利大学获得博士学位；Geophysics副主编; 先后在斯伦贝谢、壳牌、道达尔、康菲、沙特阿美等公司就职，7年国际石油公司经验；国际期刊会议论文50余篇，国际国内专利申请15个; 主要研究方向为：非常规油气地球物理，信号处理，地震干涉，水力压裂地震监测，声波与弹性波逆时偏移成像，偏移速度分析等等。
报告题目：各向异性TTI弹性波快速解耦逆时偏移和偏移速度分析
报告内容简介
Separating compressional and shear wavefields is an important step in elastic reverse-time migration, which can remove wave-mode crosstalk artefacts and improve imaging quality. In vertical (VTI) and titled (TTI) transversely isotropic media, the state-of-the-art techniques for wavefield separation are based on either non-stationary filter or low-rank approximation. They both require intensive Fourier transforms for models with strong heterogeneity. Based on the eigenform analysis, we develop an efficient pseudo-Helmholtz decomposition method for the VTI and TTI media, which produces vector P and S wavefields with the same amplitudes, phases and physical units as the input elastic wavefields. Starting from the elastic VTI wave equations, we first derive the analytical eigenvalues and eigenvectors, then use the Taylor expansion to approximate the square-root term in the eigenvalues, and finally obtain a zero-order and a first-order pseudo-Helmholtz decomposition operator. Our method allows us to efficiently solve the anisotropic Poisson’s equation in the z − k x domain. The separated vector wavefields are used to produce PP and PS images by applying a dot-product imaging condition. Several numerical examples demonstrate the feasibility and applicability of the proposed methods.