On the issue of strike or dip streamer shooting for 3D multi-streamer acquisition

Abstract

Any decision to pursue 3D multi-streamer acquisition in a certain shooting direction requires a consideration of several seismic phenomena, including subsurface illumination, spatial sampling, wave propagation, and the idiosyncrasies of seismic imaging technology. We provide both theoretical and synthetic modelling examples to provide a framework for objective discussion, so that the significance of each issue can be understood. The 2D dip-shooting requirement becomes largely irrelevant in 3D seismic acquisition. In any 3D survey location, a series of arguments may arise that supports each possible shooting direction. The key issue is that both the subsurface model and the surface acquisition geometry are intimately linked, and each must be given specific consideration during processing. Both shooting direction and shooting method (single-source vs. dual-source, parallel vs. anti-parallel, no sail line overlap vs. sail line overlap, etc.) have a direct influence upon the nature of both severe and subtle imaging artefacts arising during processing. We use synthetic and real examples to demonstrate the need for proper 3D survey planning and evaluation on a case-by-case basis, prior to any new survey.