Multiphysics of CO₂ in the subsurface: Bridging CO₂-EOR and geologic storage

Subsurface flow processes underpin two closely related yet distinct technologies in the energy transition: CO₂-enhanced oil recovery (CO₂-EOR) and geologic carbon storage (GCS). Although both rely on injecting CO₂ into porous formations, they differ markedly in their thermodynamic regimes, operational drivers, fluid compositions, and long-term objectives. CO₂-EOR is governed by miscibility, mobility control, and recovery efficiency over operational timescales, whereas GCS is dominated by trapping mechanisms, plume stabilization, and containment integrity over centuries to millennia. Where these technologies meet — particularly during the transition from active EOR to permanent storage — the coupled multiphysics of flow, phase behaviour, geomechanics, and geochemistry becomes especially complex and remains insufficiently characterized. Existing modeling and monitoring frameworks often treat the two systems in isolation, limiting our ability to transfer insight, data, and infrastructure between them.

This Research Topic aims to establish a comparative multiphysics framework that explicitly links CO₂-EOR and geologic CO₂ storage. The objective is to bring together studies that examine the shared and divergent physical, chemical, and mechanical processes governing CO₂ behaviour in the subsurface across operational and storage regimes. We invite contributions that systematically compare injectivity, plume migration, phase behaviour, rock–fluid interactions, and containment risks under EOR and GCS conditions, and that clarify how these processes evolve when a field transitions from one purpose to the other. Studies are encouraged to combine physics-based modeling — including compositional reservoir simulation and analytical or semi-analytical solutions — with data-informed methods such as machine learning and scientific machine learning (SciML), where these enhance interpretability and uncertainty quantification. Particular emphasis is placed on scale-dependent complexities, from pore-scale displacement mechanisms to field-scale operational forecasting, and on reproducible workflows that bridge theory, simulation, and field application.

The scope spans fundamental and applied research that advances a unified understanding of CO₂ multiphysics in the subsurface. Submissions are encouraged to include validation with field, experimental, or high-fidelity simulation data, and to articulate clearly how their findings differentiate, connect, or transfer between EOR and storage contexts.

To gather further insight into the multiphysics of CO₂ in the subsurface, we welcome contributions addressing, but not limited to, the following themes:

• Comparative analysis of multiphase flow, phase behaviour, and rock–fluid interactions under CO₂-EOR and GCS conditions
• Coupled thermo-hydro-mechanical-chemical (THMC) processes during CO₂ injection and storage
• Multiphysics characterization of the EOR-to-CCS transition, including operational constraints and re-purposing strategies
• Scale-dependent uncertainties in injectivity, plume evolution, and containment from pore to field scale
• Compositional reservoir simulation and history matching across EOR and storage regimes
• Pressure and rate transient diagnostics for distinguishing flow, phase, and geomechanical signatures
• Hybrid physics–data approaches (machine learning, SciML) for interpretability and uncertainty quantification in coupled CO₂ systems
• Monitoring and surveillance strategies that leverage shared infrastructure between EOR and storage operations