How we see

Opaque soil becomes a window.

We replace opaque soil and rock with a transparent porous material developed in the lab. High-speed fluorescence imaging lets us quantify transport, chemical reaction, phase displacement and deformation directly.

Injection for CO₂ sequestration, geothermal energy and wastewater disposal raises pore pressure and deforms rock. We track internal deformation and permeability as it evolves, in a sintered, rock-like transparent medium with embedded fluorescent particles.

• Flow alone can crush rock: pressurized flow makes compaction localize and couple with extensive shear.
• Afterwards the medium briefly loses stiffness, then recovers while it keeps compacting.
• Permeability evolves differently in ductile and brittle deformation.

When one fluid displaces another in a porous medium, the pore structure and the driving pressure decide the pattern. We watch fingers form, fluids mix, and surfactants reopen paths that capillary barriers had sealed.

• Inlet pressure and heterogeneity turn a uniform front into fingers; a modified Sherwood number marks the switch.
• Surfactants keep the invasion going after breakthrough by reopening throats sealed by capillary barriers.
• Heavy-tailed pore-throat distributions start the secondary invasion sooner.

Mixing, dissolution and precipitation create preferential flow paths. We measure how transport organizes itself, with experiments in which pH is visualized directly and with simulations that quantify entropy and provide the basis for a non-equilibrium thermodynamics framework.

• pH equilibrates faster than transverse dispersion or diffusion predicts.
• Reaction and flow self-organize into preferential paths, most strongly when diffusion dominates (low Péclet).
• Paths split and rejoin: bifurcations, tortuosity and fractal dimension share one power law with heterogeneity.

Cyclic injection repeatedly loads the rock with fluid pressure. Stress–strain curves show hysteresis but not where the damage sits, so we compare full strain maps of loading and unloading at the same stress.

• Same stress, different strain map: loading and unloading fields decorrelate as plastic strain builds.
• The strain correlation length grows with stress once the rock turns plastic.
• Lower permeability means longer correlation lengths.