Synthesis of phthalimide and succinimide copolymers and their evaluation as flow improvers for an Egyptian waxy crude oil

This paper describes the synthesis, characterization and performance evaluation of three phthalimide and three succinimide copolymers of vinyl acetate, styrene and methyl methacrylate as flow improvers for waxy crude oil. The prepared copolymers were named as; (VA)Ph; (St)Ph; (MMA)Ph; (VA)S; (St)S and (MMA)S. These copolymers were characterized by FTIR and 1H NMR spectroscopy. The molecular weights and nitrogen content of these copolymers were determined by using the GPC technique and the Kjeldhal method, respectively. The rheological properties of crude oil (with and without additives) were studied. From the obtained results, it was remarked that the styrene phthalimide copolymer (St)Ph exhibited the maximum pour point depression (ΔPP500 ppm = 30). The results of the rheological flow properties showed that the Bingham yield values (τβ) for crude oil without additives at 15, 27 and 39 °C were 0.286, 0.131 and 0.075 Pa respectively, whereas the τβ for the treated crude oil by the styrene phthalimide (St)Ph copolymer were 0.021, 0.0164 and 0.0081 Pa at 500 ppm at the same temperatures.