球坐标系下高波数的三维波动方程叠前深度偏移

项目名称： 球坐标系下高波数的三维波动方程叠前深度偏移

项目编号： No.41474105

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 孙伟家

作者单位： 中国科学院地质与地球物理研究所

项目金额： 90万元

中文摘要： 针对我国陡倾角复杂构造引起的高波数地震波场成像问题和叠前深度偏移方位角照明不均匀问题，本项目围绕陡倾角构造的叠前深度偏移及其方位角照明补偿这两个核心科学问题，开展如下研究工作：1)陡倾角能量保持的三维波动方程叠前深度偏移方法研究，其在球坐标系中进行数值实施易于进行球面扩散补偿，突破了经典单程波动方程叠前深度偏移的倾角限制，有效地保持叠前深度偏移高波数波场的振幅或能量；2)三维角度域共成像点道集直接生成方法及应用研究，研究复杂构造与叠前深度偏移方位角照明不均匀之间的响应特征，确定照明能量最强的优势方位角；3)构造相关的叠前深度偏移方位角照明补偿方法研究，以优势方位角的地震照明能量为依据，发展构造相关的方位角照明补偿方法，对各个方位角的叠前深度偏移进行方位角照明补偿，削弱叠前深度偏移方位角照明阴影。本项目拟解决陡倾角构造的高波数波场成像及方位角照明不均匀问题，具有重要的研究意义和实际应用价值。

中文关键词： 叠前深度偏移；波动方程；陡倾角；方位角照明；球坐标系

英文摘要： For the problems of imaging high wavenumber wavefields induced by complex geologic structures and uneven azimuth illumination of prestack depth migration, the project will study prestack depth migration method of conserving the energies of steep dip angle wavefields and its illumination compensation. The main works are as followed: 1) steep dip angle engery-conserved 3D wave equation prestack depth migration. The method is implemented in the spherical coordinate. It breaks the dip limitation of the classical one-way prestack depth migration, which can preserve the wavefileds energy at large angle. 2) 3D angle-domain common image gathers and its applications. It is used to study the characteristics of complex structers and azimuthal illumination. Meanwhile, it can determinate the predominate azimuth with good illumination. 3) structure-related azimuthal illumination compensation of prestack depth migration. According to the illumination at the predominate azimuth, the project will develop a method to compensate illumination for all azimuth and to eliminate the illumination shading. The project are proposed to solve the problems of imaging steep dip structures and uneven azimuth illumination, which has important academic significance and industrial values.

英文关键词： prestack depth migration;wave equation;steep dip angle;azimuth illumination;spherical coordinate