AVVISO DI SEMINARIO

 

10 Gennaio 2019, ore 11

 

Aula Magna “Pacinotti”

 

The Impact of Pore-Scale Flow Regimes

on Upscaling of Immiscible Two-Phase Flow in Porous Media

 

Davide Picchi

Department of Energy Resources Engineering, Stanford University, Stanford, USA

 

ABSTRACT

The development of predictive tools to model multiphase flow through porous media is critical to many industrial applications, such as petroleum engineering, carbon sequestration, and modern energy storage technologies. Although features in the topology of the flowing phases at the pore-scale (i.e., the pore-scale flow regimes) have been recently revealed by X-ray microtomography, they are still not captured by routinely used macro-scale models (i.e., Darcy's law). We tackle this problem by proposing a set of upscaled equations based on pore-scale flow regimes: the incompressible Navier-Stokes equation is upscaled by means of multiple-scale expansions and its closures derived analytically from the mechanical energy balance for different flow regimes. We show that the classical two-phase Darcy law is recovered for a limited range of operative conditions, while specific terms accounting for interfacial and wall interactions should be incorporated to accurately model ganglion dynamics. Finally, a validation of the proposed approach with the results of numerical simulations and experimental data taken from the literature is discussed. The dataset used for validation covers a wide range of systems, ranging from brine-CO2 to oil-water flows. The equations derived agree well with both numerical and experimental data.

 

 

Referente: prof. Paolo Di Marco