Instabilities and Phase Transitions in Multiphase Flow Through Porous Media: Fluids Seminar
Seminar | March 4 | 12-1 p.m. | 3110 Etcheverry Hall
Xiaojing (Ruby) Fu, Miller Fellow, Department of Earth and Planetary Sciences, University of California, Berkeley
Flow and transport through porous media is ubiquitous in nature. They are key processes behind subsurface resources such as oil and gas, geothermal energy, and groundwater. They also mediate corrosion and ageing of porous engineering materials as well as geohazards such as landslides, volcanic eruptions and earthquakes. Central to many of these processes is the strong coupling between porous media flows and phase transitionsthe creation or destruction of fluid or solid driven by thermodynamics. Multiphase flow with phase transitions often leads to dynamic systems that are far from thermodynamic equilibrium. This talk will cover two examples of nonequilibrium phenomena, and new continuum mathematical descriptions to model them. The role of mineral-dissolution reactions during geologic sequestration of carbon dioxide will be discussed first. The modeling of methane clathrate (gas hydrate) in multiphase environments using phase-field methods will then be addressed. Motivated by field and laboratory observations, a description on how the spontaneous formation of a solid hydrate crust on a moving gas-liquid interface gives rise to a new type of flow instability termed here as crustal fingering. It will further be shown that this solid-modulated gas percolation mechanism is crucial to our understanding of methane venting in the worlds oceans, gas hydrate dissociation as a trigger to landslides, and energy extraction from gas hydrate deposits. This research on fluid-solid coupling in porous media can stimulate new questions at the interface of engineering, geosciences and material sciences.