Carbon Dioxide Care: Carbon Dioxide Site Closure Assessment Research

The EU project CO2CARE “CO2 Site Closure Assessment REsearch” is established for the time period from January 2011 to December 2013. The consortium consists of partners from the EU, USA, Canada, Japan, and Australia and reflects the entire spectrum of scientific and engineering skills required. The project is funded by the European Commission and industry partners. For each CO2 storage site, approved and under operation based on permissions of the legal authorities, the final and crucial step is the abandonment of the reservoir especially with regard to long-term safety. Within this regard and following the EU Directive on geological storage of carbon dioxide (2009/31/EC) from 2009, three key topics are in the focus of the project´s research activities: well abandonment and long-term integrity; reservoir management and prediction from closure to the long-term; and risk management methodologies for long-term safety. These elements are highly site-specific, and they will be investigated in detail and in close relation to four storage sites: Ketzin (Germany), K12-B (Netherlands), Sleipner (Norway), and Otway (Australia), each representing very different (hydro)-geological and environmental settings (i.e. onshore / offshore, natural gas reservoir / saline aquifer). The portfolio of sites taken into consideration is complemented by additional locations: Wallula and Frio (USA), Nagaoka (Japan), as well as natural analogues. The research considers current practices and the regulatory framework for site abandonment and combines laboratory experiments, predictive numerical modeling and field work to develop and implement robust techniques to abandon wells and to monitor their integrity. A few wells representative of plausible scenarios when storing CO2 in a saline underground aquifer or in a depleted oil or gas reservoir is used for the validation of the techniques implemented. The outcome contributes to best practice guidelines and recommendations for well abandonment in the future and possibly also for CO2 injection well design. Consequently, for site abandonment three major questions need to be answered: Is the observed behavior of the injected CO2 conforming to the modeled behavior? Is evidence that no leakage has been detected robust? Is the site evolving towards a situation of long-term stability? The development of site abandonment procedures and technologies which guarantee the fulfillment of these requirements is the main objective of CO2CARE. A key component of the project is a Stakeholder regulatory panel that will review the research and assess its applicability to the European Regulatory framework.