Start Date/Time: Wednesday, February 11, 2009, 9:00 AM
Location: Health Sciences Building, Room T-239
'Carbon sequestration: Modeling CO2 migration and fluid-rock
Speaker Mike Bickle, University of Cambridge
Geological carbon storage in which carbon dioxide is separated from power station fuels or waste gases and pumped into storage in geological formations will play a critical role in moderating anthropogenic CO2 emissions while society develops carbon-free energy sources. The carbon dioxide needs to remain underground for at least 10,000 years. Although geological evidence shows that natural CO2 fields have existed for millions of years with minimal leakage, there is considerable interest in the fate of CO2 in the anthropogenic storage sites. A number of processes may affect stored CO2. Many of these act to retain CO2 in the reservoir. Some of the CO2 will dissolve in formation brines, some will be trapped in the porosity and some will react with silicate minerals and precipitate solid carbonate minerals. However the CO2 is lighter than the brines and will tend to rise. It is possible, although unlikely, that the CO2 or acidic CO2-saturated brines will corrode cap rocks and escape into the overlying formations. Modeling such processes is subject to significant uncertainties. However by making observations on existing CO2 storage sites and older natural CO2 reservoirs we can learn a lot about the processes which will occur in the reservoirs. I will discuss observations on the Sleipner field in the North Sea into which Statoil is pumping 1 million tons of CO2 a year and on natural CO2 field in the Colorado plateau which allow us to infer the rate at which CO2-saturated brines react with minerals in their host formations.
2008/09 WUN Earth Systems Virtual Seminar Theme: Geoengineering and Geohazards