Gas hydrates
Methane hydrate is an ice-like solid that forms out of an aqueous solution of water and dissolved methane under moderate pressure and low temperature conditions. A large body of work over the past few decades has established a fundamental understanding of methane hydrate equilibrium thermodynamics. However, modeling nonequilibrium behaviors in hydrates remains challenging.
In this series work, we develop a continuum-scale phase-field model to study gas–liquid–hydrate systems far from thermodynamic equilibrium. Specifically, we aim to understand how the formation of hydrate crust on the gas-liquid interface can impact the dynamics of methane gas displacement in ocean water column and within marine sediments.
Xenon hydrate as an analogue of methane hydrate in geologic systems out of thermodynamic equilibrium;
X. Fu, W. F. Waite, L. Cueto-Felgueroso and R. Juanes; accepted in Geochem. Geophys. Geosyst. (2019).
Nonequilibrium thermodynamics of hydrate growth on gas–liquid interface;
X. Fu, L. Cueto-Felgueroso, R. Juanes; Phys. Rev. Lett.,120(14):144501 (2018); [pdf]* Editor's suggestion
Laboratory observations of the evolution and rise rate of bubbles with and without hydrate shells;
W. F. Waite, T. Weber, X. Fu, R. Juanes, C. Ruppel; Proceedings of the 9th ICGH (2017);
Collaborators:
William F. Waite (USGS), Carolyn Ruppel (USGS), Joaquin Jimenez-Martinez (EAWAG & ETH), Bill Carey (LANL), Mark Porter (formerly LANL), Hari Viswanathan (LANL), Luis Cueto-Felgueroso (UPM & MIT) and Ruben Juanes (MIT)
Multiphase flow in porous media with phase transitions
In this series work, we study the evolution of binary mixtures far from equilibrium, and show that the interplay between phase separation and hydrodynamic instabilities in porous media give rise to new nonequilibrium phenomena. Specifically, we show that:
-
viscously unstable flow can arrest the Ostwald ripening process characteristic of non-flowing mixture;
Thermodynamic coarsening arrested by viscous fingering in partially miscible binary mixtures;
X. Fu, L. Cueto-Felgueroso, R. Juanes; Physical Review E, 94(3),033111(5) (2016); [pdf][video1][video2]
-
fluid-fluid partial miscibility exerts a powerful control on the degree of viscous fingering;
Viscous fingering with partially miscible fluids;
X. Fu, L. Cueto-Felgueroso, R. Juanes; Phys. Rev. Fluids, 2(10):104001 (2017); [pdf]
-
Pore-scale wettability and microstructure influences the morphology and dynamics of evaporative gas flow.
Pore-scale modeling of phase change in porous media;
L. Cueto-Felgueroso, X. Fu, R. Juanes; Physical Review Fluids, 3, 084302 (2018). [pdf]
Collaborators:
Luis Cueto-Felgueroso (UPM & MIT) and Ruben Juanes (MIT)
Geologic carbon sequestration
Geologic carbon dioxide sequestration entails capturing and injecting CO2 into deep saline aquifers for long-term storage. The injected CO2 mixes with groundwater, forming a mixture that is denser than the initial groundwater. The local increase in density triggers a gravitational instability at the boundary layer that further develops into columnar plumes of CO2-rich brine, a process that is referred to as convective mixing and greatly accelerates solubility trapping of CO2. Here, we investigate the pattern-formation aspects of convective mixing along with mineral-dissolution reactions during geological CO2 sequestration by means of high-resolution three-dimensional simulation.
Dissolution patterns from geochemical reactions during convection mixing in porous media;
X. Fu, L. Cueto-Felgueroso, D. Bolster, R. Juanes; Journal of Fluid Mechanics, 764:296-315 (2015); [pdf]
Pattern formation and coarsening dynamics in three-dimensional convective mixing in porous media;
X. Fu, L. Cueto-Felgueroso, R. Juanes; Philosophical Transactions of the Royal Society A, 371:20120355 (2013); [pdf][videos]
Collaborators:
Diogo Bolster (U. Notre Dame), Luis Cueto-Felgueroso (UPM & MIT) and Ruben Juanes (MIT)
Volcanology
As a Miller Fellow, I hope to apply my approaches to advance some problems in volcanology. This includes physics-based modeling of Pahoehoe lava flow, textural evolution of volcanic rocks, morphology of siliceous sinter at Yellowstone geysers and flow within dykes.
Collaborators:
Tushar Mittal (UC Berkeley), Mara Reed (UC Berkeley), Wei Lin (U. Chinese Academy of Sciences), Michael Manga (UC Berkeley), Steve Self (UC Berkeley), Kristen Fauria (WHOI)