Study on the influence of heavy oil group components on the formation and stability of W/O emulsion

In view of heavy oil B which was easy to form W/O emulsion by water flooding, this paper studied the effect of the group components of heavy oil B on the formation and stability of W/O emulsion from the separation of four-component, the characterization of group components, the determination of interface property and the evaluation of emulsion performance. The structure of the group components of heavy oil B was characterized by infrared spectroscopy and synchronous fluorescence spectroscopy. Compared with the other three group components, the asphaltene had strong polarity and high degree of association between molecules. The results of interfacial property measurement showed that asphaltene could reduce the interfacial tension of simulated oil and formation water to 10 degrees orders of magnitude and increase the interfacial expansion modulus by about 1.4-2.6 times compared with the other three group components. This was because asphaltene had strong polarity and complex aromatic structure. In order to further verify the influence of crude oil group components on the formation and stability of W/O emulsion, this paper systematically evaluated the particle size distribution and stability of emulsion formed by different group components. Compared with the saturated and aromatic, the emulsion droplets formed by resin and asphaltene simulation oil were smaller and concentrated, and the demulsification time of emulsion was prolonged by about 1.5-8 times. In summary, the influence of crude oil group components on the formation and stability of W/O emulsion was as follows: asphaltene > resin > aromatic > saturated.