Assessment of the Impact of Sedimentological Heterogeneity on Multi-Phase CO2 Injection in Shallow-Marine Reservoirs

Abstract

In this contribution we compare results between fast screening methods based on flow diagnostics with results from full-physics simulations for CO2-brine displacement. Specifically, we analyse how either method identifies the key geological features that control CO2 plume migration across an ensemble of reservoir models for the shallow marine system present in the Johansen and Cook formations of the Northern Lights project. Our results indicate that many of the heterogeneities that appear to control CO2 plume migration based on the fast flow diagnostics also control CO2 plume migration when considering the complex fluid flow physics inherent to CO2-brine displacement. However, the magnitude of impact differs between both methods, conforming the hypothesis that more complex fluid flow processes increase the impact of geological heterogeneity on reservoir flow. Our results suggest that fast-screening methods like the one proposed by Jackson et al. (2022) are a reliable approach to analyse which heterogeneities at a given storage site are most likely to control CO2 plume migration, helping geoscientist and reservoir engineers to design more meaningful reservoir models that contain the key geological heterogeneities and allow us to predict CO2 plume migration more reliably.