The capacity of geological storage of CO2 can be estimated by understanding how one of the key mechanisms for gas leakage, capillary breakthrough, behaves under sequestration conditions. The threshold pressure at which this occurs is directly related to the interfacial tension( between brine and carbon dioxide) and the contact angle of a brine droplet at a mineral surface. Since the conditions for CO2 sequestration are not easily accessible by experiments, this proposal aims to develop a series of tools to facilitate the study of brine-CO2-mineral systems via molecular simulation. This type of information can be used to get a good understanding of the breakthrough pressure for CO2 release from the rock surface and can also be used to develop molecular-level strategies for altering interfacial properties (e.g. surfactant treatments).
