Abstract
This article emphasizes that the transportation of heavy crude oil is accompanied by asphaltene deposition in pipelines, which leads to increased hydraulic flow resistance and, consequently, higher energy consumption for pumping. This, in turn, contributes to an increase in the carbon footprint of the oil production sector. The results of this study, aimed at developing energy- and resource-efficient technologies for the synthesis of a green inhibitor based on deep eutectic solvents (DESs), demonstrate the feasibility of preventing asphaltene precipitation during crude oil transportation. Within the framework of the study, asphaltenes were isolated from crude oils of the Zhanaozen and Karazhanbas fields of the Republic of Kazakhstan, model oil systems were prepared, and an environmentally friendly inhibitor based on betaine and ethylene glycol was synthesized. The model oil and the deep eutectic solvent were mixed at a 1:1 volume ratio, after which 0.15 mL, 0.25 mL, 0.45 mL, 0.65 mL, and 0.85 mL of n-heptane were sequentially titrated into the resulting mixture. Each sample was analyzed using ultraviolet (UV) spectroscopy. In samples containing the deep eutectic solvent as an inhibitor, a significant reduction in the degree of asphaltene aggregation was observed, as the inhibitor effectively slowed the agglomeration process. Accordingly, a decrease in UV absorbance intensity was recorded, indicating improved dispersion stability of the system. This effect was particularly pronounced for crude oil from the Zhanaozen field: upon the addition of 0.45 mL, 0.65 mL, and 0.85 mL of n-heptane, the absorbance values approached zero, indicating a near-complete absence of asphaltene aggregation that would otherwise hinder light transmission. The synthesis of an inhibitor based on betaine and ethylene glycol, biodegradable and low-toxicity compounds, represents a practical implementation of the "green inhibitor" concept, as confirmed by UV spectroscopic analysis and laboratory testing.