In 2012, the Celia group continued to use pore-scale models to study additional issues relevant to CO2 storage, investigating geochemically reactive systems, trapping, and hysteresis. The geochemical modeling work includes explicit modeling of both precipitation and dissolution, with the associated changes in porosity and permeability tracked as the reactions proceed. The researchers also identify conditions under which unique relationships between porosity and permeability should be expected.
Pore-scale models also provide new insights into how nonwetting fluids are trapped in porous media, including underlying mechanisms and the extent to which continuum-scale trapping functions are hysteretic or path-dependent. The hysteretic nature of all multi-phase constitutive functions can be carried from the small scale to the large scale; a study published this year shows how this can be done for Vertical Equilibrium models, and the conditions under which hysteresis may be important at the large scale.