Flows of Emulsions

Kobayashi, I., Nakajima, M. (2006). Generation and multiphase flow of emulsions in microchannels. In Kockmann, N. (Ed.). Advanced Micro and Nanosystems 5 Micro Process Engineering, Weinheim Wiley, pp. 149-171. 

The flow of emulsions, foams, and suspensions in porous media is more complex due to the nature of the particular dispersion itself. If the droplets, bubbles, or particles are very small compared with the size of the flow channels, then the nature of the dispersed phases can be largely ignored, at least for as long as the dispersion is stable. In most practical cases, however, the sizes of the dispersed species are not much smaller than the pore sizes, if at all, and the the dispersions cannot, then, be treated as pseudo-single-phase. Much more detail is available elsewhere for the flow through porous media of simple fluids [133,420], emulsions [108,227,421], foams [422,423], and suspensions [419,424,425], See also Sections 11.2.2 and 15.3. 

Kokal, S.L., Maini, B.B., Woo, R. Flow of Emulsions in Porous Media in Emulsions, Fundamentals and Applications in the Petroleum Industry, Schramm, L.L. (Ed.), American Chemical Society Washington, 1992,... 

High flow of emulsion generated by the impeller should disperse the olefin feed more quickly throughout the reactor and thereby improve quality. Comparing the FBT and HIT impellers at constant power, the flow is 40% lower for the HIT impeller. Conventional wisdom would predict the product quality to be lower. Hence impeller pumping is not the key variable. 

Predicting the Pressure Drop for Flow of Emulsions in Pipelines... 

A comprehensive review of the important factors that affect the flow of emulsions in porous media is presented with particular emphasis on petroleum emulsions. The nature, characteristics, and properties of porous media are discussed. Darcy s law for the flow of a single fluid through a homogeneous porous medium is introduced and then extended for multiphase flow. The concepts of relative permeability and wettability and their influence on fluid flow are discussed. The flow of oil-in-water (OfW) and water-in-oil (W/O) emulsions in porous media and the mechanisms involved are presented. The effects of emulsion characteristics, porous medium characteristics, and the flow velocity are examined. Finally, the mathematical models of emulsion flow in porous media are also reviewed. 

In this section we will define some of the terms used to characterize a porous medium and briefiy discuss those properties of porous materials that may have relevance to the flow of emulsions. 

Effect of Emulsion Characteristics. The flow of emulsions in porous media is affected by a large number of variables. This section describes the properties of emulsions, such as stability, quality, droplet size distribution, oil viscosity, water-oil interfacial properties, and their effect on its flow in porous media. 

Clearly, wettability will affect the flow of OAV emulsions in porous media. Many surface-active compounds (which are normally needed for stable emulsions) will alter wettability, which will then affect the flow of the oil and water phases inside the reservoir. No studies have addressed the effect of wettability on the flow of emulsions in porous media. However, some effects of wettability appear to be obvious from simple intuitive reasoning. The nature of interactions between the internal surfaces of the... 

The flow of emulsions in porous media is very complex, and to model it mathematically has been a challenge. It requires an understanding of the emulsion formation, its behavior, and its rheology inside the reservoir. Factors that affect the flow of emulsions through porous media were discussed earlier in this chapter, and the available mathematical models will be reviewed here. 

Presently, three theories describe the flow of emulsions in porous media (12) ... 

Permeability of the porous medium is not affected by the flow of emulsion through it. Alvarado and Marsden (25) and Ali and Abou-Kassem (id) account for permeability reduction that is observed by using the flowing permeability as a parameter. 

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