Novel terpolymers as viscosity reducing agent for Tahe super heavy oil

Abstract

The four components of extra-heavy oil (saturates, aromatic, resins, asphaltene) were analyzed by chemical separation. The terpolymers with different contents of styrene (S), alkyl chain (MM/DM), and vinyl acetate (V) were designed, synthesized and employed as the viscosity reducers for super heavy oil. Thus, structure and average molecular weight of the oil-soluble terpolymers were measured by Fourier-transform infrared (FTIR) and gel permeation chromatography (GPC), respectively. Comparing with the apparent viscosity of heavy oil in a wide range of shear rates (0.1-200 s-1) and temperatures (25-75 °C), it can be seen that optimal efficiency could be achieved to reduce viscosity when the terpolymer has a high percentage of long-chain alkyl. Furthermore, the molar ratio between long-chain alkyl groups and aromatic ring as well as molecular weight of terpolymers play a fundamental role in viscosity reduction of super heavy oil.