[DLS] Siqin Yu (Stanford)

“Subsurface Fluid–Rock Interactions: Multiphysics Coupling in Reactive Transport for the Energy Transition”

Fluid–rock interactions in porous media govern a wide range of subsurface processes key to the energy transition, including carbon sequestration, subsurface energy storage, and resources extraction. These interactions in porous media are inherently multiscale and multiphysics, arising from the interplay between multiphase flow, mass transport and the complex geochemical reactions occurring in the fluid phase and at the fluid-rock interface, further enhanced by the heterogeneous nature of geologic porous media.

In this talk, I investigate the impact of geochemical reactions and natural chemical heterogeneity of rocks on transport in geologic systems through the unique combination of experiments, modeling, and computation. The first part of the talk will focus on the impact that chemical heterogeneity of the rock has on dissolution dynamics. A workflow integrating rock-embedded microfluidics, physics-based modeling, and ML-enabled image segmentation will be presented. Such workflow enables one to directly calculate instantaneous dissolution rates from experimental optical measurements and to quantify the impact that gas shielding and secondary minerals have on effective reactivity. Novel correlations between effective reaction rates and gas saturation are also derived based on analytical model development and validated against experimental results. The second part of the talk will demonstrate how accurately capturing the complex aqueous-phase geochemistry is critical for fully predicting the evolution of rock surfaces during dissolution, which in turn underpins the development of reliable models for permeability evolution during coupled dissolution–precipitation processes. In this context, a pore-scale reactive transport simulator integrating multi-component mass transport, interface movement and realistic geochemical kinetics within a level-set immersed boundary method (LS-IBM) framework will be presented. After benchmarking the solver on a canonical grain dissolution problem, a fit-free forward prediction of the dissolution of an artificially fractured and chemically heterogeneous shale is performed and validated against experimental results. Finally, a latest work on olivine-rich rock dissolution and its implications for scalable carbon removal strategies will be discussed, as well plans for future research and teaching.

To conclude, these studies highlight how pore-scale heterogeneity and multiphysics coupling lead to emergent reactive behavior and richer physics. By bridging experiments and simulations across scales, this work advances a predictive understanding of fluid–rock interactions, with direct relevance for subsurface energy storage and extraction as well as carbon management.

EAPS Department Lecture Series —

Weekly talks aimed to bring together the entire EAPS community, given by leading thinkers in the areas of geology, geophysics, geobiology, geochemistry, atmospheric science, oceanography, climatology, and planetary science. Runs concurrently with class 12.S501.

Contact: eapsinfo@mit.edu