Numerical modeling of carbon dioxide injection and transport in Deep Saline Aquifers

This chapter describes the development of a compositional reservoir simulator capable of modeling multiphase transport of carbon dioxide (CO₂) in brine aquifers. As an example, it considers the radial injection of supercritical CO₂ in a brine aquifer, and results are provided that illustrate the evolution of a 2-phase fluid system in which the injected CO₂ resides in a dense supercritical phase and also dissolves into the liquid phase. Salt precipitation into a solid phase is found to occur close to the injection well where the gas phase dominates. To determine the feasibility of deep aquifer sequestration it is necessary to have a numerical model that can accurately predict the fate of CO₂ under the conditions of interest. Conditions that support the existence of supercritical CO₂ should be present at depths greater than about 800 m where pressure and temperature would be above the critical point of CO₂.