Wellbore flow model for carbon dioxide and brine

Wellbores have been identified as the most likely conduit for CO2 and brine leakage from geologic carbon sequestration (GCS) sites, especially those in sedimentary basins with historical hydrocarbon production. In order to quantify the impacts of leakage of CO2 and brine through wellbores, we have developed a wellbore simulator capable of describing non-isothermal open-well flow dynamics of CO2-brine mixtures. The mass and thermal energy balance equations are solved numerically by a finite difference scheme with wellbore heat transmission handled semi-analytically. This new wellbore simulator can take as input the pressure, saturation, and composition conditions from reservoir simulators and calculate CO2 and brine fluxes needed to assess impacts to vulnerable resources. This new capability is being incorporated into the Certification Framework (CF) developed for risk assessment of GCS sites.