Investigation into a Pour Point Depressant for Shengli Crude Oil

A new-style pour point depressant (PPD) for crude oil was prepared by mixing the aminated copolymer and the composite commercial ethylene–vinyl acetate copolymers (EVA) in fixed proportion. The aminated copolymer was synthesized by amination of terpolymer copolymerized with monomers octadecyl acrylate, maleic anhydride, and vinyl acetate. Moreover, the aminated copolymer was characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC). The interaction between components of the crude oil and the PPD was investigated by FTIR, differential scanning calorimetry (DSC), and cross-polarized light microscopy. The results showed that the PPD could form asphaltene–PPD–resin agglomerates. The new agglomerates became the efficient nucleator of the crude oil beneficiated with PPD. They changed the process of wax crystallization and greatly depressed the pour point of the crude oil.