Preparation the Esters of Oleic Acid-Maleic Anhydride Copolymer and Their Evaluation as Flow Improvers for Waxy Crude Oil

Five comb-like copolymers derived from oleic acid-maleic anhydride were prepared and then esterified by long-chain fatty alcohol (POMA C-n), where n=18, 20, 22. These polymers were characterized by FTIR and H-1 NMR analysis. The molecular weight was determined by using gel permeation chromatography (GPC). The prepared copolymers were investigated as flow improvers and pour point depressants (PPD) for crude oil. From the evaluation, it was found that, the maximum depression of PP was obtained by (POMA(2) C-22) with long-chain alcohol (C-22-OH) from 27 degrees C to 15 degrees C (PP3000ppm=-12 degrees C). On the other side, it was remarked that no depression obtained by (POMA(2) C-18), which esterified by alcohol (C-18-OH) at the same condition. The depression of pour point effectiveness was discussed on the light of polymers structure, molecular weights, and their concentrations. By analysis the results of the rheological flow properties, it was found that the POMA(2) C-22 enhanced the Bingham yield values (). The for crude oil without additives against 15, 27, and 39 degrees C were 0.286, 0.131, and 0.075Pa respectively, whereas the for the treated crude oil with POMA(2) C-22 were 0.027, 0.022 and 0.010Pa at 3000ppm at the same temperatures. By using the photomicrography analysis, it was found that, the wax morphology was greatly modified to fine dispersed crystals of compact size.