Research on a fluorine-containing asphaltene dispersant and its application in improving the fluidity of heavy oil

Abstract

The high viscosity characteristics of heavy oil make it difficult to extract, transport and process. Therefore, enhancing the fluidity of heavy oil can effectively improve the economic benefits of heavy oil resource development. Aggregation and precipitation of asphaltenes are the main causes of high viscosity of heavy oil. Asphaltene molecules are able to self-associate by intermolecular forces such as hydrogen bonding and π-π interactions, resulting in the formation of supramolecular aggregates with large particle size, leading to the increasing of viscosity of heavy oil. Fluorine is the most electronegative element and has a strong ability to form hydrogen bonds. This is due to the special role of the element fluorine, including high electronegativity and small atomic radius. In this study, the fluorine-containing copolymer was synthesized and used to disperse asphaltenes. This copolymer was also used for viscosity reduction on heavy oil in a block in Xinjiang, and the viscosity reduction rate (VRR) reached 70.25% at 600 ppm. Possible mechanism of asphaltene dispersion was proposed by fluorescence microscopy, X-ray diffractometry (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and transmission electron microscopy (TEM). The mechanism of interaction between copolymer and asphaltene by hydrogen bonds was further analyzed by infrared spectroscopy.