Under the Surface of Sleipner: What Sparse Layer Inversion Reveals About CO₂ Storage

The Sleipner project, offshore Norway marks the first successful large-scale underground carbon sequestration initiative, having stored over 18.5 million tons of CO2 by 2020. Since 1996, CO2 from nearby fields has been injected into the Utsira formation. Although time-lapse seismic data is available, the limited resolution of pre-injection data has constrained a full understanding of the reservoir’s geological structure, hindering accurate predictions of CO2 plume migration.

This paper shows the enhancement of the pre-injection seismic data through sparse layer spectral inversion, improving resolution and creating new seismic attributes, such as stratigraphic continuity and apparent time thickness. This leads to a better understanding of the geological factors influencing plume migration. The findings uncover previously unseen features in the reservoir, including both continuous and discontinuous reflections, as well as an incised channel system. These insights shed new light on the subsurface geology affecting CO2 movement, offering improved predictions for future carbon capture and storage (CCS) projects.