Steady-state, simultaneous two-phase flow in porous media: An experimental study

Abstract

We report on experimental studies of steady-state two-phase flow in a quasi-two-dimensional porous medium. The wetting and the nonwetting phases are injected simultaneously from alternating inlet points into a Hele-Shaw cell containing one layer of randomly distributed glass beads, initially saturated with wetting fluid. The high viscous wetting phase and the low viscous nonwetting phase give a low viscosity ratio M=10(-4). Transient behavior of this system is observed in time and space. However, we find that at a certain distance behind the initial front a "local" steady-state develops, sharing the same properties as the later "global" steady state. In this state the nonwetting phase is fragmented into clusters, whose size distribution is shown to obey a scaling law, and the cutoff cluster size is found to be inversely proportional to the capillary number. The steady state is dominated by bubble dynamics, and we measure a power-law relationship between the pressure gradient and the capillary number. In fact, we demonstrate that there is a characteristic length scale in the system, depending on the capillary number through the pressure gradient that controls the steady-state dynamics.

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

“…In the current study, we have investigated a system related to that of Tallakstad et al [33]. Both studies use a water-glycerol mixture as one of the two fluid phases, but where they used air as the other phase we use a commercial food grade rapeseed/canola oil.…”

“…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. Tallakstad et al [32,33] carried out associated quasi-two-dimensional experiments, using a porous Hele-Shaw cell, obtaining a power-law relation between the measured steady-state pressure difference over the cell and the applied flow rate. In a continuation of this work, [34] investigated the history dependence of the steady-state configurations observed, by increasing and decreasing the flow rates during an experiment.…”

Visualization and quantification of two-phase flow in transparent miniature packed beds

“…It is valid at least for medium-to-low flow rate, that is, capillary numbers between 10 −2 and 10 −6 . To our knowledge, few people have investigated the correlation between capillary number and breakthrough time for two-phase flow [16]. Furthermore, we were able to find a generalized and empirical correlation between the oil phase travel distance x and time t. Ferer et al have studied how the non-wetting phase moves as a function of time for two-phase drainage in 2-dimensional network structure [14,19,27,28].…”

“…It should be noted that Tallakstad et al in a system that used a flow mixture of wetting and non-wetting fluid to displace air, also measured the relation between breakthrough time and capillary number for flow in porous medium in a 85 × 42 cm 2 two-dimensional square channel [16] and found log-log correlation that had a slope of −0.89. Our system differs in many aspects from theirs, most notably in that flow was generated in a micro-channel packed bed where primary drainage was manifested.…”

“…This process is known as displacement, and has been studied largely in the past few decades due to its importance to reservoir engineering, hydrology, agricultural irrigation and treatment of ground water contamination [5][6][7][8][9][10][11][12][13][14][15][16][17].…”