Shear-wave Reflection-seismic Pilot Study at the UNIS CO2 Lab site, Longyearbyen, Svalbard
I. Lecomte, U. Polom, G. Sauvin, B.O. Ruud, H. Christiansen and G. Gilbert
Event name: 76th EAGE Conference and Exhibition 2014
Session: Seismic Acquisition
Publication date: 16 June 2014
Info: Extended abstract, PDF ( 738.48Kb )
Price: € 20
As part of the world’s needs for CO2-injection test sites, the city of Longyearbyen in Svalbard is an interesting location for testing technologies related to carbon capture and storage (CCS) in a vulnerable arctic environment, being a closed energy system with a coal-fuelled power plant. Therefore, the University Centre in Svalbard (UNIS) established the UNIS CO2 Lab site a few km away of Longyearbyen. The local geological structures appear suited for storing CO2 at about 600-900 m depth and injection tests are carried out. Monitoring micro-seismicity during and after injection is important, but to properly analyse micro-seismicity, a good velocity model for both P- and S-wave is necessary. The top 100-m of the site, including permafrost, is however difficult to assess. In an attempt to improve the actual velocity model near the surface, a pilot study of S-wave reflection seismic was carried out in 2012 and is reported here. Despite numerous noise sources, including wind and strong surface waves, a profile acquired on a nearby filled road showed promising results, indicating very low S-wave velocity values down to 200 m/s, thus giving a much better image of the top 70-m than P-wave seismic earlier acquired. Lessons learned are given too.