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JUSTIFICATION OF PARAMETERS OF THE 2D CDP FIELD SYSTEM

A. P. Sysoev

А. P. Karpinsky Russian Geological Research Institute, Saint Petersburg, Russia

When performing seismic observations, 2D seismograms of a common shot point are represented as a discrete function of two variables, i.e. time and receiver – source offset. When recording a wave field using single seismic receivers placed small distance apart (UniQ technology), two goals are pursued : maintaining high frequencies of reflected signals by eliminating the effect of microstatics and fulfilling the Kotelnikov sampling theorem when discretizing a continuous field with respect to a spatial variable, thereby eliminating the effect of spatial aliasing of regular interference waves. At the stage of digital processing, this allows to solve the problem of extracting useful signals and suppressing noise more effectively. Taking the idea of a close array of receivers as a whole, it is proposed to optimize the profile observation system by source – receiver spacing combining analog and digital grouping of seismic receivers. In this case, the spatial sampling of the field is determined by the distance between the centers of receiver groups, and the parameters of the analog – digital grouping are calculated from the condition of suppressing spatial aliasing frequencies. Based on the analysis of static corrections obtained during processing of previous seismic studies, a method is proposed for assessing the effect of lateral microstatics variations on the results of analog grouping.

Keywords: 2D observation system, digital – analog grouping, microstatics, spatial aliasing.

DOI 10.20403/2078-0575-2020-3-59-65