CO2 Storage: Drying Effects in Saline Aquifers

[SubsurfaceDS]

Hi Everyone,

I'm working on a project to evaluate potential mineral precipitation during CO2 storage. I'm currently creating simple equilibrium models and adding the CO2(g) in the equilibrium phases at a set pressure. I'm curious about the drying effects of injecting CO2 which can lead to salt precipitation in saline formation waters (1). In a model this would involve water evaporating into the CO2(g). Is it possible to model these types of multi-phase interactions in PHREEQC? If so, how could I go about adding it to my input file?

Any insight you can provide is greatly appreciated!
Kara

1) Celia, M. A., Bachu, S., Nordbotten, J. M., and Bandilla, K. W. (2015), Status of CO2 storage in deep saline aquifers with emphasis on modeling approaches and practical simulations, Water Resour. Res., 51, 6846– 6892, doi:10.1002/2015WR017609.

[dlparkhurst]

PHREEQC does not have any multiphase flow capabilities.

It does have the capability to simulate gas-water equilibrium. You can use GAS_PHASE to model a multi component gas phase, including CO2(g), H2O(g), and other components. As dry CO2 gas bubble would incorporate H2O if it included as a component. As  a consequence, water would be removed from the aqueous phase, increasing concentrations of solutes.

PhreeqcRM is a module designed to couple with transport models. Use with multiphase flow is less common, but is possible.