InterPore2023

A simplified pore-scale model for drainage including film flow effects

22 May 2023, 17:15

15m

Oral Presentation (MS06-A) Physics of multiphase flow in diverse porous media MS06-A

Speaker

Dr Paula Reis (University of Oslo)

Description

During drainage in porous media, film flow through networks of corners and capillary bridges can establish connections between seemingly isolated defending fluid clusters. Coupled with the drainage through the bulk of pores and throats, the flow through these networks constitutes a secondary drainage mechanism that can significantly affect final fluid configuration and residual saturations. We propose a simple numerical model that incorporates such mechanism by modifying the cluster identification algorithm in an invasion percolation model for drainage. In the model, which represents quasi-2D porous media, wetting-phase-filled sites are considered available to invasion when connected to the liquid outlet directly through successions of pores and throats, or through chains of interconnected capillary bridges. Within the available sites, the order of invasion follows a hierarchy of local capillary pressure thresholds that can be perturbed to accommodate gravitational and viscous effects. With the proposed model, recently obtained experimental data of drainage of Hele-Shaw cells filled with spheres were reproduced, showing good qualitative agreement. In particular, we investigated the existence of an active zone where film-flow-related events are more likely to occur, the capillary bridges size and spatial distributions, and the impact of film-flow drainage on the residual saturation.

References

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Vorhauer, N., Wang, Y. J., Kharaghani, A., Tsotsas, E., & Prat, M. (2015). Drying with formation of capillary rings in a model porous medium. Transport in Porous Media, 110(2), 197-223.

Hoogland, F., Lehmann, P., Mokso, R., & Or, D. (2016). Drainage mechanisms in porous media: From piston‐like invasion to formation of corner flow networks. Water Resources Research, 52(11), 8413-8436.

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