InterPore2022

Comparison of the Generalized Network Model to Direct Numerical Simulation for Two-Phase Flow

2 Jun 2022, 14:15

15m

Oral Presentation (MS09) Pore-scale modelling MS09

Speaker

Mr Luke Giudici (Imperial College)

Description

A thorough understanding of pore-scale modelling techniques is essential to flow through permeable media research. We compare two phase-flow simulations from the generalized network model (GNM) [Raeini et al, 2017, 2018] with a recently developed lattice-Boltzmann model (LBM) [Akai et al, 2018, 2020] for drainage and waterflooding in two samples — a synthetic beadpack and a micro-CT imaged Bentheimer sandstone — under water-wet, mixed-wet and oil-wet conditions. Macroscopic capillary pressure analysis reveals good agreement between the two models, and experiments, at intermediate saturations but shows large discrepancy at the end-points. At a resolution typically used in research settings, the LBM is unable to capture the effect of layer flow which manifests as abnormally large initial water and residual oil saturations. Critically, pore-by-pore analysis shows that the absence of layer flow limits displacement to invasion-percolation in mixed-wet systems. The GNM is able to capture the effect of layers, and exhibits predictions closer to experimental observations in water and mixed-wet Bentheimer sandstones. Overall, we present a workflow for the comparison of pore-network models with direct numerical simulation of multi-phase flow. We demonstrate that the GNM is an attractive option for cost and time-effective predictions of two-phase flow, and show that care must be taken when selecting pore-scale models.

References

Akai, T., B. Bijeljic, and M. J. Blunt (2018). Wetting boundary condition for the color-gradient lattice Boltzmann method: Validation with analytical and experimental data. Advances in Water Resources 116 (April), 56-66.

Akai, T., Q. Lin, B. Bijeljic, and M. J. Blunt (2020). Using energy balance to determine pore-scale wettability. Journal of Colloid and Interface Science 576, 486-495.

A. Q. Raeini, B. Bijeljic, and M. J. Blunt, Generalized network
modeling: Network extraction as a coarse-scale discretization of the void space of porous media, Phys. Rev. E 96, 013312 (2017).

A. Q. Raeini, B. Bijeljic, and M. J. Blunt, Generalized network
modeling of capillary-dominated two-phase flow, Phys. Rev. E
97, 023308 (2018).