Fanning

By increasing marine streamer separation progressively from the head to the tail of the streamer, the spread takes on the appearance of a fan. Streamer fanning may improve and evenly distribute coverage at the far offsets, without compromising seismic data resolution or quality. It may also increase acquisition efficiency by reducing infill.

Streamer fanning
Fanning reduces infill without compromising data

Streamer fanning may be accomplished a variety of ways. The term is used to describe the ability to increase the streamer separation, in a marine seismic acquisition spread, progressively from the head to the tail. The resulting streamer spread has a fan-like appearance when viewed from above. Fanning may improve and evenly distribute coverage at the far offsets, without compromising seismic data resolution or quality. Ultimately this may increase acquisition efficiency by reducing infill.

One approach to fanning uses lateral steering devices, and a variety of such devices are available on all our GeoStreamer® 3D vessels. This has become a common mode for MultiClient operations. Recent surveys using our proprietary technology report a reduction in infill of 3-5 percentage points.

Using our proprietary Nucleus® infill management tools (Infill Prediction, Modeling, and QC), fan configurations can be planned and managed based on survey-dependent geophysical criteria.Traditional coverage specifications related to flex-binning have been replaced by model-based infill specifications and coverage QC.