二维滤波在频域偏移中的应用

THE APPLICATION OF 2-D FILTERING TO FREQUENCY DOMAIN MIGRATION

1. 同济大学;2. 江苏石油勘探开发公司

在频率波数域进行波动方程迭加偏移时,首先要对水平迭加地震剖面进行二维付氏变换,然后对该二维谱值进行相移运算。在定点运算的计算机上进行相移运算相当费时。利用二维滤波可节省相移运算量,并可提高资料处理质量。但是,如果二维滤波的参数选择不够合适,将会导致同相轴的“蚯蚓化”。本文通过理论和实际资料的处理给出选择二维滤波参数的准则。

To conduct the wave equation stack migration in frequency wave-number domain, the 2-D Fourier transform has to be, in the first place, performed for horizontal stacked seismic section and after that the phase shift operation for 2-D spectral value should be followed. From practice we learn that it is very time-consuming to have phase shift operation on fixed point computer. However, it will safe a lot of operational amount using 2-D filtering and also it might help improve the quality of data processed. But should the parameter of 2-D filtering be not so appropriately chosen it would result in the presentation of event "earthworm" like. Moreover, the criteria regarding how to pick up the 2-D filtering parameters based on the theoretical and field data processed are given in the paper.