Evaluating the benefits and limitations of black-oil models for simulating CO2 storage in saline aquifers

This study compares PVT properties using compositional and two-phase models, also known as black-oil models, to accurately simulate CO2 storage in saline aquifers. Additionally, these PVT models assessed into the reservoir models using commercial simulators (Eclipse E100 and CMG-GEM) to explore different simulation approaches for reservoir-scale geological CO2 storage in saline aquifers. Furthermore, the effect of composition-specific phenomena such as evaporation and salt precipitation, which cannot be captured by the black-oil model, on the overall plume migration, CO2 injectivity, and storage capacity is also investigated. The accuracy in predicting CO2-brine PVT properties and the superior computational efficiency of black-oil simulations make this approach appealing for large-scale geological storage of CO2 in saline aquifers. However, high salinity brine and near-wellbore effects, such as salt precipitation due to water vaporisation, can limit the application of black oil models for CCS projects.