Abstract
Improving understanding of CO 2 migration, phase change, and trapping processes motivates the development of large-scale laboratory experiments to bridge the gap between bench-scale experiments and field-scale studies. Critical to the design of such experiments are defensible configurations that mimic relevant subsurface flow scenarios. We use numerical simulation with TOUGH2/ECO2M and ECO2N to design flow and transport experiments aimed at understanding upward flows including the transition of CO 2 from supercritical to liquid and gaseous forms. These experiments are designed for a large-scale facility such as the proposed laboratory for underground CO 2 investigations (LUCI). LUCI would consist of one or more long-column pressure vessels (LCPVs) several hundred meters in length filled with porous materials. An LCPV with an insulated outer wall corresponds to the column being at the center of a large upwelling plume. If the outer wall of the LCPV is assigned fixed temperature boundary conditions corresponding to the geothermal gradient, the LCPV represents a narrow upwelling through a fault or well. Numerical simulations of upward flow in the columns reveal complex temporal variations of temperature and saturation, including the appearance of liquid CO 2 due to expansion cooling. The results are sensitive to outer thermal boundary conditions. Understanding of the simulations is aided by time-series animations of saturation-depth profiles and trajectories through P-T (pressure-temperature) space with superimposed phase saturations. The strong dependence of flow on hydrologic properties and the lack of knowledge of three-phase relative permeability and hysteresis underlines the need for large-scale flow experiments to understand multiphase leakage behavior.
Original language | English (US) |
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Pages (from-to) | 279-303 |
Number of pages | 25 |
Journal | Greenhouse Gases: Science and Technology |
Volume | 2 |
Issue number | 4 |
DOIs | |
State | Published - Aug 2012 |
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Environmental Chemistry
Keywords
- ECO2M
- TOUGH2
- expansion cooling
- liquid CO
- long-column flow experiments
- upward CO leakage