Effect of Various Polymeric Crystal Modifiers and Solvents Formulations on the Prevention of Wax and Asphaltene Formation in Crude Oil Pipelines

Transportation of crude oil from offshore platform to onshore has been recognized as one of the challenges faced by oil and gas industry as the pipelines are deposited by wax and asphaltene. This research investigated the efficiency of three types of crystal modifiers, namely ethyl-vinyl acetate (EVA25 and EVA40), and styrene maleic anhydride (SMA); and two types of solvents, methylcyclohexane (MCH) and para-xylene, in different ratios to formulate the best inhibitor. The best formulation for EVA-based inhibitor was 30 wt% crystal modifiers and 70 wt% para-xylene, while the best formulation for SMA was 30 wt% SMA and 70 wt% MCH which could give viscosity reduction as high as 86.37%. All three types of crystal modifiers showed almost the same efficiency. Para-xylene was found to be the best solvent as it acted as solvent for the crystal modifiers and also as the asphaltene dispersant. The efficiency of the inhibitor decreased when the solvent used was a combination of two types of compounds. An optimization study showed that the most optimum conditions were found to be 42.02%, 3.34% and 54.65% for EVA25, MCH and para-xylene respectively.