Hild structure multi-azimuth seismic experiment

Abstract

Illumination of complex structures has always been a matter of discussion. While in the ‘old’ days it was preferable to shoot in the dip direction of the main structural trend, the recent advances in processing have led us towards shooting in the most ‘economical’ direction. The recent development of OBC (Ocean Bottom Cable) acquisition has provided us with high-fold multi-azimuth data and has demonstrated dramatic improvements in the image quality. Already in 1996 a test was carried out by Elf (in Gabon) acquiring four surveys at different azimuths across a salt body (Houllevigue, H.., Delesalle, H., and De Bazelaire, E., 1999). The result of this experiment showed the incomplete but complementary information extracted from the various acquisition directions. PGS carried out the same kind of experiment across the Norwegian Varg field where they shot two surveys at 600 from the old existing survey (Hegna, S. and Gaus, D., 2003). The published results showed improved imaging at the reservoir level.