Heavy oil as an emulsion: Composition,structure, and rheological properties

Recent works devoted to studying the structure and rheological properties of water/oil disperse systems have been reviewed. Contemporary understandings of crude heavy oil as a water-in-oil emulsion have been discussed. Data on the mechanism of the stabilizing effect of natural lipophilic surfactants and ultradispersed particles of different natures contained in oil have been presented. Methods that are used to improve the transport characteristics of heavy oil—in particular, the formation of low-viscosity oil-in-water emulsions—have been listed. Colloidal and rheological properties of heavy oil-in-water emulsions, which are increasingly applied for pipeline transportation of oil, have been considered.