文章基本信息

标题：Preliminary Investigation of Wavefield Depth Extrapolation by Two-Way Wave Equations
本地全文：下载
作者：Bangyu Wu ; Ru-Shan Wu ; Jinghuai Gao 等
期刊名称：International Journal of Geophysics
印刷版ISSN：1687-885X
电子版ISSN：1687-8868
出版年度：2012
卷号：2012
DOI：10.1155/2012/968090
出版社：Hindawi Publishing Corporation
摘要：Most of the wavefield downward continuation migration approaches are relying on one-way wave equations, which move the seismic energy always in one direction along depth. The one-way downward continuation migrations only use the primaries for imaging and do not treat secondary reflections recorded on the surface correctly. In this paper, we investigate wavefield depth extrapolators based on the full acoustic wave equations, which can propagate wave components to opposite directions. Several two-way wavefield downward continuation propagators are numerically tested in this study. Recursively implementing of the depth extrapolator makes it necessary and important to eliminate the unstable wave modes, that is, evanescent waves. For the laterally varying velocity media, distinction between the propagating and evanescent wave mode is less clear. We demonstrate that the spatially localized two-way beamlet propagator is an effective way to remove the evanescent waves while maintain the propagating mode in laterally inhomogeneous media.