Research on the Mechanism of Characteristic Change in Water-in-Oil-in-Water Multiple Emulsion during Porous Media Seepage

Compared with oil-in-water (O/W) emulsions, water-in-oil-in-water (W/O/W) multiple emulsions have a more complex composition and structure of the dispersed phase, and the viscosity change rule under shear is more complicated due to the presence of reversed-phase emulsifiers in the dispersed phase. The effects of different factors on the rheology of multiple emulsions were investigated by rheometer, and the viscosity values of multiple emulsions and oil-in-water emulsions were compared at the same time. Finally, the flow pressure change characteristics of multiple emulsions and oil-in-water emulsions were compared using core flow tests. The secondary emulsification of multiple emulsions occurred during the Seepage process, thus maintaining the complexity of the internal phase structure and the characteristics of multiple interfaces, proving the emulsification effect of multiple emulsions on the original aqueous phase in the core during the Seepage process, and found that the emulsification of multiple emulsions in the Seepage process made the produced liquid portion of multiple emulsions show the bicontinuous characteristics by confocal microscopy.