Performance improvement on the cold flow properties of crude oil with high asphaltene by adjusting the polarity of the third monomer in polymers

Asphaltenes and waxes are the primary factors affecting the cold flow properties of crude oil. In this paper, based on the binary polymer of acrylate-maleic anhydride (PM 22 -MA), different third polar groups of acrylamide, N -(hydroxymethyl) acrylamide, N -phenylacrylamide (NPA), and styrene (SM) were introduced to synthesize a series of ternary pour point depressants (PPDs) to explore the effect of asphaltene on the cold flow properties of Xijiang (XJ) crude oil. Thereinto, PM 22 -MA-NPA containing amide group and benzene ring exhibited the best depressive effect, which decreased pour point by 14°C at 1500 ppm. The mechanism of interaction of the polar groups in PPDs with asphaltene was studied. The polar groups could form stronger hydrogen bonds with asphaltene, delaying the asphaltene macromolecule bonding, allowing the synergistic effect of PPDs and asphaltene to be better utilized to improve the cold flow properties of crude oil. Furthermore, the dipole moment magnitude and electron cloud density were calculated with Gaussian. It was found that the polar group with a dipole moment magnitude of 3.2244 debye and an electron cloud density ranging from −1.6364 to 1.9944 eV was the most suitable third polar monomer for the PPDs of XJ crude oil.