Date of Award
May 2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Energy Engineering
First Advisor
Olusegun S. Tomomewo
Abstract
Geological storage of carbon dioxide (CO₂) in deep saline aquifers (DSAs) offers enormous potential for large-scale emissions mitigation, yet its deployment remains constrained by the limited predictive capability of conventional modeling approaches. Existing studies often isolate individual processes or rely on reduced-order formulations, which limit their ability to resolve the tightly coupled chemo-hydro-mechanical (CHM) dynamics that govern injectivity, containment, storage efficiency, and project economics.
This study tests the hypothesis that a fully-coupled modeling framework is essential to capture the multi-domain interactions controlling CO₂ storage performance at field scale. A full-physics modelling framework integrating geological, hydrodynamic, thermodynamic, geochemical, geomechanical, and operational controls is developed and evaluated using four performance objectives: net emissions potential (NEP), containment security (S), capacity utilization (U), and levelized cost of storage (LCOS).
The results demonstrate that storage performance is governed by threshold-driven, non-linear interactions, between aquifer properties, subsurface processes and injection strategy. Fully coupled simulations reveal emergent system behaviors that are absent in reduced-order models, including near-well transients, brine density anomalies, delayed post-injection caprock failure, spatially heterogeneous mineralization, and pressure-limited injectivity. Sensitivity analysis shows that accessible pore volume, boundary conditions, operational design, and capillary heterogeneity exert first-order control on NEP and containment security. Optimized well configurations, extended injection duration and higher injection rates improved reservoir sweep and capacity utilization, but simultaneously accelerated containment degradation and the risk of cost escalation.
These findings confirm the central hypothesis, and demonstrate that high-fidelity, fully coupled models are both practically feasible and necessary for realistic assessment of CO₂ storage systems. The proposed framework with its integrated controls and performance objectives, provides a robust tool for model benchmarking, multi-objective optimization, and project-level decision-making, with direct implications for storage design and regulatory evaluation.
Recommended Citation
Omobude, Osemoahu, "A Full-Physics Multi-Objective Framework For Sustainable CO2 Storage Modelling In Deep Saline Aquifers" (2026). Theses and Dissertations. 13968.
https://commons.und.edu/theses/13968