A description of the Statoil Sleipner Project

The offshore Sleipner gas field is located in the middle of the North Sea. Since September 1996, wells in the field have been injected with 1 Mt of carbon dioxide per year without any major operational problems. The Sleipner Project is the world-leader in commercial scale carbon dioxide injection into a deep saline aquifer. The carbon dioxide is injected into the Utsira formation, a sand layer containing salt water. The reservoir is capped by a shale layer. The Saline Aquifer CO{sub 2} Storage (SACS) is a multidisciplinary project initiated by a consortium of energy companies from Europe wishing to collect information about carbon dioxide injection in the Utsira formation and other underground structures in the North Sea. Seismic surveys have successfully monitored the carbon dioxide in the Utsira formation, along with the movement of the injected carbon dioxide within the reservoir. The surveys indicate that carbon dioxide migrates upward within the reservoir. The shale layers act as a temporary barrier to this upward migration. A new EC supported project will extend this study. The CO2STORE project will examine the long term fate of the injected carbon dioxide and evaluate other monitoring methods that are more cost effective than seismic surveys. The new project will apply the knowledge gained from SACS to develop plans for 4 site-specific carbon dioxide storage operations both offshore and onshore. 9 figs.