径向道滤波法去线性干扰

RT filter attenuating the linear noise

中国石化石油勘探开发研究院南京石油物探研究所,江苏南京 210014

Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Development, Nanjing 210014, China

径向道变换(RTT)是一个简单的几何地震道集映射算法。在径向道域中,通过不同径向道参数设计,可以 大大降低线性干扰(如直达波、折射波、面波、空气波等)的频率,因此可以将它们从地震记录的波场中区分开来, 然后用带通滤波器把它们从原始道集中滤除掉。该方法可以分离或衰减多波多分量勘探中的强线性噪音,其去 噪效果比单纯的带通滤波效果好,在某些情况下甚至比F-K滤波的效果还好。径向道滤波法容易实现,滤波 效果明显,波形不发生畸变,能较好地保存浅层有效波振幅信息。

The radial trace transform is a simple geometric mapping algorithm of a seismic trace gather, which moves seismic wavefield data from the conventional co-ordinates of lateral distance and traveltime to those of apparent velocity and traveltime. It can deduce the frequency of the linear noise (such as direct arrivals, refractions, ground roll, etc) with designing different RT parameters. And separate them from seismic wavefield, and then a band-pass filter is used to subtract them from the origin seismic trace gather. The technique is present by using it to sequentially separate and attenuate several modes of strong linear noise on a 3-C geotechnical seismic survey. The result of attenuating noise,RT filter is better than the single band filter,or better than F-K filter in the some time. The RT filter is a particularly flexible and effective method, which has no distortion and can preserve the seismic amplitude information for shallow layers.