叠前深度偏移在深水崎岖海底地震资料的应用

深水勘探近年来成为海上勘探的热点,这不可避免会碰到崎岖海底的情况.在崎岖海底的地震资料中,地震波的传播路径受海底影响严重畸变,速度横向变化剧烈,导致下伏地层严重扭曲变形,时间偏移无论叠前还是叠后均不能改变这种情况.三维叠前深度偏移对构造复杂及速度的横向变化均没有条件限制,所以成为解决崎岖海底成像的有力工具.本文即以南海...

Application of Pre- stack Depth Migration to Seismic Data from Rough Deep Sea Bottom

In the seismic data from rough deep sea bottom,the path of seismic wave is seriously distorted by the sea bottom,and lateral velocity is changed greatly,causing lower strata to be distorted,and the time migration can not change the situation with the post-stack or the pre-stack.The 3D pre-stack depth migration（PSDM） can be used to solve the problem,because it has no limitation to the complex structure and the change of the lateral velocity change.In this paper,it takes an example of PSDM in the Zhujiangkou Basin of South China Sea,it illustrates the process,technique and effect.It includes the pre-process of the ocean seismic data,the foundation of sea bottom layer,the CVI（Constrainted Velocity nversion）,the introduction of gradient,the foundation of solid model and the whole tomography velocity refined and so on.