Flow and Reactive Transport of Miscible and Immiscible Solutions in Fractured & Porous Media

Miscible and immiscible flows are important phenomena encountered in many industrial and engineering applications such as hydrothermal systems, oil and gas reservoirs, salt/water intrusion, geological carbon sequestration etc… Under the influence of gravity, the flow of fluids with sufficiently large density ratios may become unstable leading to instabilities, mixing and in some instances reactions at the interfacial contact between fluids. Flow is governed by a combination of momentum and mass conservation equations that describe the flow of the fluid phase and a convection-diffusion equation describing the change of concentration in the fluid phase. When hydrodynamic instabilities develop it may be difficult to use standard grid-based methods to model miscible/immiscible flow because the domains occupied by fluids evolve constantly with time. In the current study, adaptive mesh refinement finite elements method has been used to solve for flow and transport equations. Furthermore, a particle tracking scheme has also been implemented to track the kinematics of swarm of particles injected into the porous fractured media to quantify surface area, sweeping zones, and their impact on porosity changes. Spatial and temporal moments of the fingering instabilities and the development of reaction zones and the impact of kinetic reaction at the fluid/solution interfaces have also been analyzed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.