Eleventh Year Annual Report: Carbon Storage
The Storage Group works to evaluate the effectiveness and safety of geological CO2 sequestration. The group's large-scale modeling investigations of the challenges of CO2 sequestration in saline aquifers are complemented by field-based analyses, bench-scale laboratory experiments of flow in porous media, pore-scale network modeling, and molecular-scale modeling of processes relevant to carbon storage.
The PI's of the Storage Group are Michael Celia, Pablo Debenedetti, Athanassios Panagiotopoulos, Jean-Hervé Prévost, Howard Stone, and Jeroen Tromp.
- Comparison of areas suitable for shale and tight gas production and those suitable for CO2 storage show significant overlap, indicating potential conflict in subsurface usage and reduction of CO2 storage capacity due to fracturing of possible caprock formations.
- In situ determination of effective wellbore permeability shows a range from about 1 milliDarcy to about 50 Darcy, values much larger than one would expect from intact cement and in the range of reservoir permeabilities.
- Efficient multi-scale models are simulating a wide range of practical, large-scale problems and show good agreement with full-physics simulators.
- Simulations suggest that successful implementation of full-scale CO2 injection operations will likely require active reservoir management through brine production, along with innovative strategies for resource utilization.
- Detailed analyses have been performed using our in-house simulator dynaflow to investigate the effects of thermal stresses on wellbore and cap-rock integrity.
- Pore-scale network models can provide insights and quantitative information about hysteresis and phase trapping in two-phase displacements, and about impacts of geochemical reactions on changes in porosity and permeability.
- Using bench-scale experiments and theory, a new hydrodynamic instability has been identified with relevance for flow in porous media.
- Modeling and experimental studies indicate self-similar behaviors for gravity current propagation in and leakage from porous media in some specific cases.
- State of the art molecular simulation techniques have been successfully applied to the calculation of the phase behavior of carbon dioxide-brine mixtures under conditions relevant to carbon capture and storage.
- New simulations of methane hydrate formation are the first to show nucleation in the absence of an interface.
- Simulations confirm that inclusion of poroelastic behavior is important for description of physical properties of reservoirs.