ABSTRACT
Any investigation program is a function of the proposed structure – shallow, intermediate or deep foundations, and the anticipated ground conditions. Desk studies are often the most cost-effective item in the site investigation process. A desk study may reveal facts that cannot be discovered in any other way. Despite these merits, the desk study phase tends to be skipped too often due to lack of awareness. Geophysical investigations over large areas are required for both anchor spreads for floating facilities especially in deep water where the footprint is large, for subsea field architecture and offshore wind farms. They reveal seabed features (e.g. sand waves, potential obstructions) and subsurface ground conditions (e.g. layering, faulting and the presence of shallow gas or hydrates). Surface vessel anchoring points and seafloor pipelines cover many square kilometres. Moreover, since deep piles are no longer used, the depth investigated is shallow, at most 30 m below seafloor.
