Flow Mechanisms, Relative Permeabilities, and Coupling Effects in Steady-State Two-Phase Flow through Porous Media. The Case of Strong Wettability

Abstract

The pore-scale flow mechanisms and the relative permeabilities during steady-state two-phase flow in a glass model pore network were studied experimentally for the case of strong wettability (θe < 10°). The capillary number, the fluid flow rate ratio, and the viscosity ratio were changed systematically, while all other parameters were kept constant. The flow mechanisms at the microscopic and macroscopic scales were examined visually and videorecorded. As in the case of intermediate wettability, we observed that over a broad range of values of the system parameters the pore-scale flow mechanisms include many strongly nonlinear phenomena, specifically, breakup, coalescence, stranding, mobilization, etc. Such microscopically irreversible phenomena cause macroscopic nonlinearity and irreversibility, which make an Onsager-type theory inappropriate for this class of flows. The main effects of strong wettability are that it changes the domains of the system parameter values where the various flow regimes are observed and increases the relative permeability values, whereas the qualitative aspects of the flow remain the same. Currently, a new true-to-mechanism model is being developed for this class of flows.

Steady-State Two-Phase Flow in Porous Media: Review of Progress in the Development of theDeProFTheory Bridging Pore to Statistical Thermodynamics Scales

“…The porous medium was modelled as a three-dimensional Payatakes and Dias (1984) Pore-tomesoscale Network models for 2ϕFPM Dias and Payatakes (1986a, b Hinkley et al (1987) SS2ϕF in planar and non-planar model networks Avraam et al (1994) Flow regimes and relperms during SS2ϕFPM Avraam and Payatakes (1995) Reveal of latent experimental evidence on the existence of OOC for SS2ϕFPM Valavanides (2010) Flow regimes and relperms during SS2ϕFPM / strong wettability Avraam and Payatakes (1999) Experimental works Figure 1 Milestones in the DeProF theory evolution spanning three decades. DeProF is the apex of the "Payatakes group" research efforts on the study of Steady-State two-phase Flow in Porous Media (SS2ϕFPM), combining experimental research, theoretical analysis, numerical simulations and semianalytical and mechanistic modeling.…”

Film flow dominated simultaneous flow of two viscous incompressible fluids through a porous medium

“…After a characteristic time, such systems reach a steady-state configuration where macroscopic flow parameters fluctuate around stable values. Concerned with determining relative permeability and qualitatively describing different flow regimes in this state, Payatakes and co-workers conducted extensive experimental, numerical, and theoretical studies on this type of flow [9,[22][23][24][25][26][27]. Later, Knudsen et al [28], Knudsen and Hansen [29,30], and Ramstad and Hansen [31] have investigated fractional flow properties and cluster formations in steady-state two-phase flow, using 2D network simulations.…”

Oil Fragmentation, Interfacial Surface Transport and Flow Structure Maps for Two-Phase Flow in Model Pore Networks. Predictions Based on Extensive, DeProF Model Simulations

“…With recent advances in imaging technology, these flows are observed in real porous media as well (Georgiadis et al, 2013;Oughanem et al, 2015;Rücker et al, 2015). The observed flow structures show a significant and À presumably À systematic mutation ranging from practically no oil-flow, to large and small oil ganglion dynamics, to drop traffic and connected pathway flow mixtures, depending À primary À on the flow conditions and À secondary À on the physicochemical, size and network configuration of the oil-water-p.m. system Payatakes, 1995 and1999;Krummel et al, 2013;Armstrong et al, 2016). These studies show that during simultaneous flow of oil and water, the disconnected phase (oil) contributes significantly to the total flow and, in certain cases even exclusively, e.g.…”

“…To this end, extensive simulations implementing the DeProF algorithm for systems similar to those studied by Avraam and Payatakes (1995;1999) have been carried-out to derive maps that describe the dependence of the flow structure on the independent flow variables, namely the capillary number, Ca, and the flow rate ratio, r, or, equivalently, the reduced, superficial velocities of oil and water. The simulations span 5 orders of magnitude in Ca (À 8 logCa < À 3) and r(À 2 logr 2).…”