Modelling the impact of film flow and adjustable surface tension in reservoir flow management

Studying fluid flow in porous media is essential for various applications which include hydrocarbon extraction, groundwater management, sequestration or oil and gas extraction. Drainage efficiency influences recovery, storage capacity, and the long-term stability of reservoirs. During primary drainage, invasion of a non-wetting fluid through pore bodies and throats leaves behind trapped and disconnected clusters of wetting fluid leading to higher residual saturation. Recent studies have shown that capillary bridges and corner films can connect such trapped clusters and enable their subsequent drainage.

This work develops a pore-network model that incorporates film flow and adjustable surface tension on a 2D porous matrix generated by Random Sequential Adsorption and analyzed via Delaunay–Voronoi geometry. Pore pressure–volume relations are derived from a Young–Laplace description and combined with Poiseuille-type fluxes. In addition, pressure diffusion is studied on heterogeneous pore networks with fractal-like geometry, to quantify how this type of structure controls the spreading of pressure and dissolved species at the surface.

The objective of this study is to investigate how such film flows enhance connectivity and reduce residual saturation during drainage. Additionally, the transport of dissolved species that modify wetting properties and surface tension will be modeled, exploring their impact on flow efficiency. By combining numerical simulations with theoretical analysis, our work aims to quantify the impact of surface-chemical interactions on macroscopic flow behavior, providing new insights into optimizing fluid displacement and improving efficiency in subsurface processes.