Review of the Geological Security of Carbon Dioxide Storage in the Deep Saline Aquifers of Norway

Semere Solomon
The Bellona Foundation, Oslo, Norway

Carbon dioxide capture and storage is one option for mitigating atmospheric emissions of carbon dioxide and thereby contributes in actions for stabilization of atmospheric greenhouse gas concentrations. Information and experience gained from the injection of CO₂ in a large number of existing enhanced oil recovery projects, industrial analogues, underground natural gas storage projects around the world and acid gas injection projects, provide additional indications that CO₂ can be safely injected and stored at well-characterized and properly managed sites. This paper reviews published literature on the geological security of storing carbon dioxide in deep saline aquifers at the Sleipner Gas Field project in Norway. Nearly 1 MtCO₂ has been successfully injected annually in the deep saline aquifers of the Utsira formation since 1996 with no leakage. Available geological information shows absence of major tectonic events after the deposition of the Utsira formation implying a tectonically stable environment. Micro-seismic studies suggest that the injection of CO₂ in sands of the Utsira Formation can not trigger any measurable events. The site is well characterized and the CO₂ injection process was monitored using both time-lapse seismic and gravity methods which provided insights into the geometrical distribution of the injected CO₂ and verified safe injection. The injected CO₂ will potentially be trapped geochemically. Solubility trapping has the effect of eliminating the buoyant forces that drive CO₂ upwards, and through time it can lead to mineral trapping, which is the most permanent and secure form of geological storage. Overall, the study at the Sleipner area demonstrates the geological security of carbon dioxide storage in deep saline aquifers.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece