Evaluation of Poly(Eicosyl Methacrylate‐ co ‐Vinyl Acetate) as a Potential Flow Modifier for Low Waxy Crude

ABSTRACT In this work, a novel copolymer of eicosyl methacrylate (EMA) and vinyl acetate (VA), poly(EMA‐ co ‐VA), was synthesized via free radical polymerization technique to be used as a flow modifier for waxy crude. From Size Exclusion Chromatography (SEC) analysis, the molecular weight (MW) of poly(EMA‐ co ‐VA) fall in the range from 4600 to 10,600 g/mol with quite narrow polydispersity index (PDI) values (1.18–1.44). The synthesized poly(EMA‐ co ‐VA) were obtained by varying monomer ratios and further rheological and morphological studies were carried out to evaluate it as a potential flow modifier for Indian waxy crude. The crude oil used in this study contains only 1.5 wt% paraffinic wax and hence classified as low waxy crude. The results showed that poly(EMA‐ co ‐VA) can strongly interact with paraffinic wax crystals present in crude, that significantly enhances the rheological and morphological properties. Gelation point of blank crude was found to be 15.1 ° C. With the addition of poly(EMA‐ co ‐VA) with EMA and VA ratio 2:3, the gelation point of crude oil reduced to 3.6 ° C at 2000 ppm concentration which is about 76.2%. Furthermore, the apparent viscosity of crude showed maximum reduction of 87.3% at 0°C, with the addition of poly(EMA‐ co ‐VA) with EMA and VA ratio 2:2 and 4:2 at 3000 ppm concentration. The morphological analysis of paraffinic wax crystals in crude oil revealed that the synthesized polymer strongly interacts with the paraffinic wax crystals, effectively reducing their size and inhibiting further growth. The results provide substantial evidence of the improvement in the low‐temperature flowability of waxy crude through the synthesized poly(EMA‐co‐VA). Although, the synthesized poly(EMA‐ co ‐VA) showed better performance in improving the flow ability of low waxy crude, its effectiveness as flow modifier for heavy crude oil will be investigated in subsequent studies.