Synthesis and performance analysis of stearoyl chloride-modified copolymers as pour point depressants for waxy crude oil

This research focuses on the synthesis and evaluation of stearoyl chloride-modified copolymers as advanced solutions for improving the flow ability of waxy crude oil. The study addresses the critical issue of wax crystallization, which leads to significant flow resistance at low temperatures, by developing polymeric additives with optimized molecular architectures. The synthesized additives include polyethylene glycol 400 monooleate (PEG 400 MO), poly(2-ethylhexyl acrylate) (Poly 2-EHA), copolymer CO-80:20 (80% 2-EHA: 20% PEG 400 MO), and its modified version with stearoyl chloride, CO-80:20 Modified. Structural characterization using Fourier-transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC) confirmed their molecular integrity and weight distributions. The effectiveness of the additives was quantified through pour point measurements and rheological analyses conducted at 9°C, 15°C, and 27°C. The modified copolymer CO-80:20 demonstrated a 55% reduction in pour point and a 65% reduction in viscosity, showcasing its ability to inhibit wax crystal formation and enhance flow ability in waxy crude oil. Despite a slight steric hindrance, its dual-functionality design outperformed simpler additives, making it a promising solution for tackling low-temperature flow challenges. These findings emphasize the critical role of advanced copolymer modifications in minimizing energy consumption and addressing operational challenges in the transport of waxy crude oil.