Diffusion phenomena analysis for CO2 storage purposes

The Earth’s climate is increasingly altering by human activities. One of the concerns is related to the concentration of greenhouse gas in the atmosphere. The most significant greenhouse gas is CO2. Consequently, the amount of CO2 must be decreased. This can be accomplished by means of carbon dioxide capture and storage (CCS), also known as CO2 sequestration. The entrapment of CO2 in the oil reservoirs during CO2-based EOR has recently started to be considered to use in conjunction. It is a win-win project in which the recovery factor can be increased, while the amount of greenhouse gas emissions- reduced. The costs of CO2 capture and storage can, in many cases, be compensated by improved recovery. To ensure long-term secure storage, it is necessary to take into account a number of possibilities of failure of CO2 sequestration, such as diffusion of CO2 through seal rock, loss of the seal rock integrity, etc. The diffusion phenomena analysis for CO2 storage purposes was the scope of this study. The current thesis presents a critical review of technical literature dedicated to the description of the diffusion phenomena, the introduction of different diffusion coefficient measurement methodologies, characterization of diffusion coefficients through laboratory experiments. Furthermore, a number of diffusion coefficients provided by literature are reported and analyzed.