Studies on the interfacial dilational rheology of films containing heavy oil fractions as related to emulsifying properties

In this research, the heavy oil emulsifying and viscosity reducing properties of a series polyethers have been studied by the emulsion stability analysis and viscosity measurements. The experimental results show that the polyethers (with molecular weights of 8400, 12,600 and 14,600) are efficient surfactants for heavy oil emulsification and viscosity reduction. To illustrate the mechanisms, we carried out the study of interfacial properties by interfacial tension and dilational rheology measurements. The experimental results show that the resins and asphaltenes in heavy oil have strong interfacial activity. The adsorption of active components will form interfacial film with certain intensity, which may help to form stable W/O emulsion. On the other hand, the adsorption of polyethers will reduce interfacial tension and form sub-layer construction at higher concentration, which leads to the formation of elastic interfacial layer with a certain strength. For the mixed systems of active components with polyethers, the mixed interfacial layers show almost the same properties just as polyethers used alone, demonstrating that the interfacial layers will be occupied mainly by polyether molecules. The water-soluble polyether with suitable molecular structure will form strong interfacial film, which may be helpful for forming stable O/W emulsion and reducing viscosity of heavy oil obviously.