Studies on the influence of long chain acrylic esters polymers with polar monomers as crude oil flow improver additives

This study investigated the efficiency of 22 polymer additives of defined and controlled structural characteristics in improving the flow properties of crude oil. The additives were synthesized by the solution polymerization of alkyl acrylates of various alkyl chain lengths with styrene, acrylic acid and 1-vinyl-2-pyrrolidone as copolymers or terpolymers. Polymerization was performed by tert-butylperoxy-2-ethylhexanoate as initiator in xylene at 92 °C, up to high conversion. The influence of polymerization conditions on additive composition and properties, and their effect on the pour point and rheological properties of crude oil samples from the fields of Števkovica, Obod and Đeletovci located in the northern Croatia were studied. Additive efficiency was dominantly influenced by the alkyl acrylate chain length. The influence of component with carboxyl functional group or heterocyclic-nitrogen compound on additive quality was less obvious. Additive efficiency significantly depended on the properties of crude oil, and n-paraffin content and distribution. The main advantage of the process is that additives can be directly used without purification.