Dual Azimuth 4D in the Barents Sea
In the height of the Covid pandemic, Vår Energi commissioned PGS to conduct a dual-azimuth 4D monitor survey over their Goliat field in the Barents Sea. Challenges included complex multiples which can mask the 4D signal and a short Barents Sea weather window.
Johan Leutscher, Geophysical Operations and QC Manager, and Alex Bertrand, Principal Geophysics Advisor from Vår Energi tell us more. Johan says ‘After four years of production we decided it was time to conduct the first monitor survey to compare with our baseline survey. Our aim is to assess fluid movement in the reservoir to optimize future drilling campaigns. Alex says 'The 4D acquisition was conducted by PGS and finished ahead of schedule. PGS managed the difficult situation with the ongoing Corona pandemic in a very professional way. Processing is ongoing and the first data delivered by PGS is expected early 2021.'
Ramform Tethys ensured a stable, reliable platform and towed 14 streamers with 50 m separation in two azimuth directions to deliver a high-density multisensor GeoStreamer survey.
Advanced source and streamer steering enabled accurate matching of the monitor with the baseline and towing GeoStreamer deep ensured reduced noise. Using GeoStreamer for the monitor allowed upgrading of the baseline for better compatibility and the detection of reservoir changes. SWIM processing will provide effective multiple removal.