Eliminating Marine 4D Positioning Errors - Ho Close Are We? A North Sea Case History

摘要

We present a North Sea 4D acquisition case history that achieved very high repeatability as a result of detailed planning and the use of a new automated and integrated vessel, source and receiver control system. The new control system virtually eliminates source positioning errors. Streamer feather matching to a baseline survey is shown to be highly repeatable through the use of steerable streamers and shooting each line at the appropriate time in the tidal cycle. The combination of these two factors lead to excellent feather matching despite a +/- 7 degree natural feather variation. Results from the survey show that 94% of the co-binned traces had a combined source and receiver positioning error of less than 25m from their planned positions.