摘要
在逆时偏移过程中界面产生的反射波会对偏移结果造成低频干扰,为了能够提高偏移结果的信噪比,在逆推过程中将反射波进行压制是一种有效的方法。本文首先介绍了双程声波方程逆时传播的差分格式,在实现了双程声波方程逆时偏移的基础上,运用无反射波方程、Poynting矢量和Robinson公式三种反射波压制方法进行反射波的压制,并对它们各自的可行性及适用性进行了对比分析。分析结果表明无反射波方程只有在小角度入射的情况下,才会有较好的压制效果;Poynting矢量和Robinson公式的效果较好,但对于上、下行波重合的情况,Poynting矢量法会压制掉有效波的信息,而Robinson公式法则会保留有效波的信息。
In the process of reverse time migration,reflection wave caused by the interface will bring low-frequency artefacts to the migration profile.To improve the SNR（Signalnoise ratio）of migration results,suppressing reflection wave during back-propagating is an efficient method.In this paper,firstly we present the difference scheme of the two-way acoustic wave equation during back-propagating.Based on the implement of the two-way acoustic wave equation reverse time migration,we use nonreflecting wave equation,Poynting vector and Robinson formula to suppress reflection wave.In addition,we analyze the effectiveness and applicability of the three methods.Analysis results show that nonreflecting wave equation will work only under small incidence angle;Poynting vector and Robinson formula get better results,but for the overlapping situation with upgoing and downgoing wave,Poynting vector will suppress the useful information,Robinson formula will retain it.
出处
《工程地球物理学报》
2013年第4期480-486,共7页
Chinese Journal of Engineering Geophysics
