Large-Scale 3D High-Resolution Near-Surface Imaging over Nordkapp

The 3700km2 Nordkapp Basin area, Barents Sea, was recently acquired with a wide-spread source-over-spread design. With its 6 sources sitting on top of 18 multi-sensor streamers, one sail-line can record a dense carpet of 108 sublines separated by only 6.25m. By thinly sampling the near offset over the full azimuth, this new source-over-spread setup is particularly well suited to image the steeply dipping salt flanks that extend up to the water-bottom. After application of a dedicated processing sequence carefully designed to honour the full resolution of the recorded data, the obtained high-resolution image is able to distinguish even small-scale geological features. This large 3D volume was also compared with an NFH image. Using the full benefits of the hexa-source, a high-end processing sequence was applied to the NFH data to overcome the usual weak signal-to-noise ratio of such records. The comparison between the two final images confirms the high-resolution quality of the source-overspread volume, which includes enhanced lateral resolution, especially along the crossline direction, and access to AVO and RMO information. On the other hand, the very thin vertical sampling of the NFH data extends the recorded bandwidth by two octaves, making it a possible complement to the source-over-spread image.