Broadband processing improves 4D repeatability and resolution at the Sleipner CO2 storage project, North Sea

The Sleipner natural gas field situated in the Norwegian sector of the North Sea is the worlds longest-running industrial-scale CO2 storage project. The CO2 injection commenced in 1996, inserting almost one million tonnes (1MT) of CO2 per year into the Utsira Fm. By 2020, over 18 MT of CO2 had been securely stored. The acquisition and processing used for Sleipner CO2 seismic monitoring program has evolved over several years in a successful and cost-effective monitoring program. Employing up-to-date processing technologies, including broadband solutions and 3D demultiple, has recently helped to reduce uncertainties in 4D interpretation and increased the resolution needed to reveal new details of the CO2 plume movement. Within the Utsira Fm., it is now possible to track some thin shale layers that can be important for predicting future growth of the CO2 plume. The deeper layers of CO2 are more well-defined. These have been historically difficult to interpret due to poor imaging in the previous 4D datasets.