Foam transport

Flow of trains of surfactant-laden gas bubbles through capillaries is an important ingredient of foam transport in porous media. To understand the role of surfactants in bubble flow, we present a regular perturbation expansion in large adsorption rates within the low capillary-number, singular perturbation hydrodynamic theory of Bretherton. Upon addition of soluble surfactant to the continuous liquid phase, the pressure drop across the bubble increases with the elasticity number while the deposited thin film thickness decreases slightly with the elasticity number. Both pressure drop and thin film thickness retain their 2/3 power dependence on the capillary number found by Bretherton for surfactant-free bubbles. Comparison of the proposed theory to available and new experimental... 

Kovscek, A.R. Radke, C.J. Fundamentals of Foam Transport in Porous Media in Foams, Fundamentals and Applications in the Petroleum Industry, Schramm, L.L. (Ed.), American Chemical Society Washington, 1996,... 

In this chapter, we discuss much of the work accomplished since Fried, but without attempting a complete review. Useful synopses are available in the articles and reports of Hirasaki (2, 3), Marsden (4), Heller and Kuntamukkula (5), Baghidikian and Handy (6), and Rossen (7). Our goals are to present a unified perspective of foam flow in porous media to delineate important pore-level foam generation, coalescence, and transport mechanisms and to propose a readily applicable one-dimensional mechanistic model for transient foam displacement based upon gas-bubble size evolution [i.e., bubble or lamella population-balance (8, 9)]. Because foam microstructure or texture (i.e., the size of individual foam bubbles) has important effects on flow phenomena in porous media, it is mandatory that foam texture be accounted for in understanding foam transport. 

This discussion follows the goals listed previously. First, we describe how foam is configured within porous media, and how this configuration controls foam transport. Next, we review briefly pertinent foam generation and coalescence mechanisms. Finally, we incorporate pore-level microstructure and texture-controlling mechanisms into a population-balance to model foam flow in porous media consistent with current reservoir-simulation practice (10). Attention is focused on completely water-wet media that are oil free. Interaction of foam with oil is deferred to Chapter 4. 

Kovscek Radke Fundamentals of Foam Transport in Porous Media... 

Do not fill the foam Transportation, overburdened the hidden trouble of... 

Tetrabromobisphenol A di-2-hydroxyethyl ether Tetradecabromodiphenoxybenzene Tetrakis (2-chloroethyl) ethylene diphosphate Tris (2,3-dichloropropyl) phosphate flame retardant, EPS Tribromophenyl allyl ether flame retardant, ethyl cellulose Diphenyl octyl phosphate flame retardant, ethylene copolymers Ethylenebis (tetrabromophthalimide) flame retardant, expandable PS Dibromoethyidibromocyclohexane Tetrabromobisphenol A bis (allyl ether) Tetrabromocyclooctane flame retardant, extruded PS Tetrabromocyclooctane flame retardant, fabrics Antimony pentoxide Methylphosphonic acid, (5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl methyl ester flame retardant, fibers Antimony pentoxide Tetrabromoethane flame retardant, filament winding Epoxy resin, brominated flame retardant, film Tetrabromobis (2-ethylhexyl) phthalate flame retardant, fire-retardant material Chlorinated paraffins (C12, 60% chlorine) Chlorinated paraffins (C23, 43% chlorine) flame retardant, flexible PU foam bedding Tetrakis (2-chloroethyl) ethylene diphosphate flame retardant, flexible PU foam furniture Tetrakis (2-chloroethyl) ethylene diphosphate flame retardant, flexible PU foam transportation Tetrakis (2-chloroethyl) ethylene diphosphate flame retardant, flexible PU foams furniture, automobile seating... 

Figure 18. Foam transport in a long core (oil free, foam quality 98%).

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