Direct numerical simulation (DNS) of flow in porous media plays an increasingly important role in understanding pore-scale flow physics and obtaining constitutive parameters for upscaling, thanks to the improvement of numerical models and increase in computational capability. Inertial effects are largely ignored in such simulations as the bulk Reynolds number (Re) is very small. However, recent micromodel experiments of liquid CO2 displacing water show that the local velocity bursts could result in much higher local Re than the bulk Re, thus the inertial effects may not be negligible in modeling CO2 sequestration. Fully considering the inertial effects in a physical scCO2 – brine flow system imposes a requirement on the ratio of viscosity over surface tension that the model can handle, where many traditional models either cannot fulfill this requirement or cannot perform practical 3D simulations on real rock samples.
In this talk, I will first introduce our in-house developed and GPU-accelerated “MF-LBM-v2” code[1], which is based on some latest developments of the lattice Boltzmann multiphase models. With improved numerical stability from using the advanced models and an order of magnitude speedup from GPU acceleration, the code is able to account for the inertial effects of the physical scCO2 – brine flow system with complex pore geometries. I will then give two successful stories[1, 2] where the code was employed to study scCO2 – brine displacement in a sandstone sample and two different micromodels, revealing new insights into CO2 sequestration.
References
1. Chen, Y., et al., Inertial Effects during the Process of Supercritica CO2 Displacing Brine in a Sandstone: Lattice Boltzmann Simulations based on the Continuum-surface-force and Geometrical Wetting Models. Water Resources Research, 2019. 55(12): p. 11144– 11165.
2. Jiménez-Martínez, J., et al., Homogenization of Dissolution and Enhanced Precipitation Induced by Bubbles in Multiphase Flow Systems. Geophysical Research Letters, 2020. 47(7): p. e2020GL087163