Seismic applications > Processing of a shot point

The shot points recorded for seismic surveys are usually corrupted by surface waves such as pseudo-Rayleigh waves. For seismic imaging based on reflected waves, it is necessary to be able to separate weak reflected events from high energy surface waves. Wave separation is a crucial step in the processing sequence. We show the benefit of combining two different wave-separation methods in order to remove all the energetic wave-field. The conventional F-K method is used to filter surface waves and converted refracted waves. The SVD method (Singular Value Decomposition) is then used to extract refracted waves. The different step of the processing sequence are: amplitude recovery, deconvolution by spectrum equalization, wave separation by SVD and F-K filters, normal move-out (NMO) with constant velocity for quality control.

The shot point presented here is an end –on spread composed of 96 traces. The distance between 2 adjacent geophone is 1 m. The source is a weight dropper. The animation describes the different processing steps. At each step the data are shown both in the time- distance domain and in the frequency – wavenumber domain ( F-K domain).