对多分量地震资料P-和SV-波场分解

在多分量地震勘探资料中,水平和垂直分量都记录有P波和SV波。本文研究了P波和SV波波场分解的方法。当上行P波和S波分别入射时,通过研究它们引起的水平和垂直位移,把地震记录的水平和垂直分量进行分解,得到纵波和转换波;在已知海底介质中纵横波速度和介质密度的情况下,可以在τ-P域内实现波场分解,然后变换到时间域,得到时间域内的纵波和转换波剖面。把本文研究的波场分解方法应用于合成资料,能够有效地分解得到纵波波场和转换波波场。最后,海上多分量实际资料的实例应用表明,本文研究的波场分解方法是可行有效的。本方法也适用于自由表面的资料。

Separation of P-and SV-wavefields from multi-component seismic data

In multi-component seismic exploration, the horizontal and vertical components both contain P-and SV-waves. The P-and SV-wavefields in a seismic record can be separated by their horizontal and vertical displacements when upgoing P-and SV-waves arrive at the sea floor. If the sea floor P wave velocity, S wave velocity, and density are known, the separation can be achieved in theτ-p domain. The separated wavefields are then transformed to the time domain. A method of separating P-and SV-wavefields is presented in this paper and used to effectively separate P-and SV-wavefields in synthetic and real data. The application to real data shows that this method is feasible and effective. It also can be used for free surface data. This research is sponsored by National Natural Science Foundation of China (No. 40272041) and Innovative Foundation of CNPC (NO. 04E702). Liu Daoli, a Master’s candidate at Peking University, received hi s BS in geophysics from multi-component seismic data processing. E-mail: daolipku@gmail.com Hu Tianyue, see biography in Applied Geophysics, 2004, 1(1), p.19.. Wang Yanbin, Vise professor of Peking University.