Coupled wellbore-reservoir modelling to evaluate CO2 injection rate distribution over thick multilayer storage zones
Document Type
Article
Publication Date
10-1-2023
Abstract
Technical and economic feasibility of Geologic CO2 Storage (GCS) projects requires maximizing the amount of stored CO2 per unit pore space of the storage zone per well. Considering injection through a fully penetrating vertical well in a multi-layer thick aquifer, CO2 would be unevenly distributed over the aquifer thickness, underutilizing the available pore space. In this work, we use coupled wellbore-reservoir modelling to investigate the interplay between the parameters that control CO2 pore-space filling. Flow capacity profile and gravity/buoyancy override are the primary factors controlling CO2 flux into a layered system. In addition, a higher fraction of CO2 would flow into the aquifer top layers due to the difference in the hydrostatic pressure gradient between the well and the aquifer. Also, movement of CO2/brine interface within the wellbore, and temporal change in the average fluid mobility within layers can affect rate profile. Results show that CO2 rate distribution is solely controlled by the flow capacity profile and pressure difference when gravity is insignificant. Conversely, the injected CO2 is biased towards the aquifer top when buoyancy is strong. Higher gravity numbers amplify this behavior. Results also indicate that strong gravity may lead to underutilizing the bottom perforations which can trigger brine backflow and causes CO2-brine interface to rise within the wellbore. Pauses in the injection would amplify backflow which could increase salt precipitation near the wellbore affecting injectivity and rate distribution. Overall, we find that it may not be possible to reproduce the results of the coupled model using decoupled models.
Publication Source (Journal or Book title)
International Journal of Greenhouse Gas Control
Recommended Citation
Abdelaal, M., & Zeidouni, M. (2023). Coupled wellbore-reservoir modelling to evaluate CO2 injection rate distribution over thick multilayer storage zones. International Journal of Greenhouse Gas Control, 129 https://doi.org/10.1016/j.ijggc.2023.103987
