The sequestration of CO2 into deep geologic formations is currently discussed as a potential way to mitigate the greenhouse effect by reducing the concentration of CO2 in the atmosphere. Separation of CO2 from flue gases of power plants and injection into the subsurface could help in reducing CO2 emissions. It is intended that the injected CO2 remains stored in the formation for centuries. Since CO2 is less dense than water at the conditions in such formations, there is potential for the CO2 to leak through confining layers (cap-rock) back to the atmosphere.
This project deals with the modelling of the plugging of damaged or fractured cap-rock in injection well vicinity in a CO2 storage reservoir and the protection of well cement against corrosion using biofilms. This involves the development of a concept to model biomass accumulation in a porous medium on the Darcy scale and should account for bacterial growth, deposition of bacteria on the porous medium, detachment of attached biomass, decay and the effects of biofilm growth on the hydraulic properties of the porous medium. Such a model could have other applications such as in the plant nutrient transport in soils.