Monitoring small amounts of CO2 injected into a thin reservoir structure - results from the Ketzin pilot site

In the past decades, an increasing atmospheric concentration of carbon dioxide has been observed which is generally considered as the main cause of global warming and resulting climate change (IPCC 2005). Capture and geological storage of carbon dioxide (CCS) are discussed as one option to reduce greenhouse gas emissions while continuing the use of fossil fuels as long as they are available and as long as renewables and increased energy efficiency cannot replace fossils completely (Bachu 2003). Large scale storage projects which are currently in operation, such as, e.g. the Sleipner field offshore Norway (Arts et al. 2004) and the In Salah project in Algeria (Ringrose et al. 2009), are related to oil and gas production. Smaller scale projects covering different geological settings have been implemented worldwide, with a special focus on advancing monitoring technologies (e.g. Kikuta et al. 2005; Michael et al. 2010).