Performance evaluation of the gamma-irradiated (EVA/ Hydrocarbon)-blends as flow improvers for waxy crude oil

As the alkyl chain length of the prepared pour point depressant plays a key role in its efficiency, this study explores a novel approach to enhancing the drawbacks of EVA-copolymer as a flow improver for waxy crude oil by blending it with various hydrocarbons containing C16 and C18 alkyl chains (namely; oleic acid, palmitic acid, and 1-bromohexadecane) and exposing the blend to gamma ionizing radiation (50 kGy). Spectroscopic analysis of the prepared modified EVA-copolymer was investigated, illustrating the attachment of the produced radicals produced from the radiolysis of the hydrocarbons on the polymer skeleton of EVA-copolymer. The modified EVAcopolymer were incorporated by different concentrations (100, 500, 1000, 2000 and 5000 ppm) into crude oil and demonstrated a remarkable reduction in pour point (Delta PP = 42 degrees C and 39 degrees C) at 2000 ppm concentration, significantly more effective than unmodified EVA (Delta PP = 33 degrees C), despite unmodified EVA more effective at 5000 ppm. Additionally, substantial viscosity and shear stress reductions were observed in most modified EVA copolymers, particularly at temperatures near the pour point, with a marked decrease in the yield point. This highlights the potential of utilizing gamma ionizing radiation to develop high-performance EVA-copolymer pour point depressant for crude oil.