3D seismic imaging without stack: a case history from the Irish sea

Abstract

Conventional 3D marine seismic surveys usually employ high-fold Common Midpoint (CMP) stacking techniques, long streamers, and elaborate positioning systems to determine both the source and receiver array locations for every shot. It is inevitable that the reflection responses occurring in seismic profiles obtained through the CMP stack process are spatially averaged. Responses are further averaged over a range of reflection incidence angles in consequence of the various offset distances represented in the CMP gather. Whilst these effects may benefit the continuity of reflected events in a processed section, they detract from the potential resolution that could be achieved through subsequent 3D migration and obscure detail that might otherwise contribute to a more rigorous interpretation.