Practical applications of CO$_2$ flow modeling in commercial scale sequestration projects

We review various challenges related to modeling of CO$_2$ flow through porous media, in the specific context of commercial scale sequestration projects of multiple millions of tons per year. Proper understanding and modeling of the physics of rock- CO$_2$ and rock-brine interactions have dramatic implications for CO$_2$ plume spread, and the final ``fate'' of the injected CO$_2$. We demonstrate the practical relevance of these concepts on specific geologic sites that are currently being developed for commercial scale sequestration in the United States.