An integrated approach to characterize fliud-rock interactions during CO₂ injection

Accurate characterization of fluid rock interactions is crucial for de-risking of CO₂ injection operations. In this contribution we describe an integrated approach to reconstruct relative permeabilities and capillary pressure functions using experimental core flooding results for the case of the Nini West depleted offshore oil field, Danish North Sea, which is currently being planned for CO₂ storage. Since CO₂ will be transported to the storage site by ship, the injection will be intermittent with high CO₂ injection rates. Core flooding experiments are designed to mimic periodic CO₂ injection with variable rates. The accompanying petrographic studies and geochemical experiments suggest that the core flood can be modelled using the immiscible isothermal formulation. The resulting brine-CO₂ unsteady flow data are used to solve the inverse problem to determine the parameters of the relative permeability and the capillary pressure functions.