Source signature repeatability and source array directivity — Measurements from the Valhall 4D survey

Abstract

The two issues of source signature repeatability and source array directivity have been considered in great detail by many authors. Loveridge et al. (1984) discuss the effects of source array directivity on source signature deconvolution. It has become common practice to use a single far field source signature to remove the source signature from the recorded seismic data, consequently it is understood that the source signature must be consistent from shot to shot. The two issues of source array directivity and source signature repeatability become even more critical for time‐lapse seismic surveys, where the source array is assumed to be invariant from shot to shot, survey to survey and for all source receiver azimuths. The purpose of our study was to quantitatively measure differences in the source signature in these two domains: shot to shot variations and survey to survey variations.