Phase under continuous flow review

In this chapter the properties of nonaqueous hydrocarbon foams will be reviewed and the effects of foam formation on flow of oil—gas mixtures in porous media will be discussed A laboratory technique for investigating the role of foamy-oil behavior in solution gas drive is described, and experimental verification of the in situ formation of non-aqueous foams under solution gas drive conditions is presented The experimental results show that the in situ formation of nonaqueous foam retards the formation of a continuous gas phase and dramatically increases the apparent trapped-gas saturation. This condition provides a natural pressure maintenance mechanism and leads to recovery of a much higher fraction of the original oil in place under solution gas drive. 

For continuous development, the mobile phase is allowed to traverse the layer under the influence of capillary forces until it reaches a predetermined position on the plate, where it is continuously evaporated. Evaporation of the mobile phase usually occurs at the plate atmospheric boundary by either natural or forced evaporation. The movement of the mobile phase to the air boundary occurs by capillary flow, but once it reaches the boundary, additional forces are applied by evaporation of the solvent. Eventually a steady state (constant velocity) is established, where the mass of solvent evaporating at the boundary is equivalent to the amount of new solvent entering the layer. Sandwich-type chambers for continuous development were reviewed by Soczewinski [124]. Perry [125] has outlined the use of the short-bed continuous development chamber for optimized continuous development with variable selection of the plate length, and Nurok [126] has proposed a theoretical model to optimize experimental conditions. Continuous development is used primarily to separate simple mixtures with a short development distance and a weaker (more selective solvent) than employed for conventional development [8]. It is not widely used in contemporary practice. 

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