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.

To assess the influences of various parameters in ultra deep (>4km), high temperature, fractured geothermal systems, the system's NPV was evaluated as these parameters were varied. The examined fracture network had multiple fractures leading between the wells in a single doublet. The tested input parameters concern rock matrix parameters (permeability, porosity, thermal conductivity and heat capacity), apertures in the fracture network and cold-water injection rates. After simulation of flow, the resulting data has been used for the calculation of NPV, which provided an indication for the performance. Larger values for matrix parameters and higher fracture apertures amplified each other's positive effect they had on the NPV of the system, as they both prevented bottlenecked flow of injected water from injector to producer wells and kept the system lifetime longer by allowing injected water more time to absorb heat before reaching the production well. An optimum exists when selecting injection rate with regards to system NPV. Lower injection rates lead to lower energy production, while higher injection rates lead to shorter lifetimes. A balanced injection rate lead to a maximum NPV. More investigation into optimization of injection rate over system lifetime will prove valuable for maximizing performance.