The ultimate milestone for wide-tow multi-source acquisition has recently been achieved in the Barents Sea. In September 2020, Ramform Tethys conducted a seismic survey with a penta-source configuration delivering 315 meter total separation.
In the examples from two adjacent surveys in the Barents Sea, reservoir targets can be found above the first water-bottom multiples. Near-offset information is critical for accurately delineating prospects and to conduct AVO studies. The first figure below illustrates the gain in ultra-near offset coverage achieved with the respective wide-tow triple and penta-source configurations. The ultra-wide penta-source solution demonstrates excellent coverage which is free of near-offset gaps between sail lines.
Ultra-near offset coverage calculated from the navigation data belonging to two adjacent wide-tow source surveys in the Barents Sea in 2020. The ultra-wide tow penta-source solution delivers almost gap-free coverage of the first offset class, while keeping the same efficiency.
Details of the shallow complex geology are revealed both on timeslices and cross-sections, including diffractions (figure below). The comparison exemplifies how modern towed-streamer acquisition can be tailored to meet the geophysical and geological challenges in a time and cost-effective manner. The processing and velocity model building have started and the first imaging results will be available very soon.
Timeslice and cross-section extracted from the ultra-near offsets acquired by wide-tow triple source and the ultra-wide penta-source as shown in the figure above. The water depth is about 400 m and targets are expected as shallow as 600 m. The data in these examples are raw and still show multiples and source bubble energy. Sail line boundaries are no longer visible in the area acquired with the penta-source.