The synergistic effect between imidazole reagents and kinetic hydrate inhibitors

Abstract

In recent years, kinetic hydrate inhibitors (KHIs), as an important hydrate control method, have received extensive attention in the oil and gas industry. During the usage of KHIs, it is often necessary to add KHI synergists to maximize their hydrate inhibition performance. Therefore, the development of synergistic reagents with high-efficiency to improve inhibition performance of the KHIs is of great significance for the prevention and treatment of hydrates. In this work, we screened a series of imidazole reagents as KHIs synergists through experiments, and studied the synergistic mechanism between imidazole reagents and KHIs by molecular simulation. Our results demonstrate that the addition of low concentrations of imidazole reagents alone has no obvious inhibitory effect on methane hydrates, but show obvious synergistic hydrate inhibition effect with KHIs. Among the tested imidazole reagents, 2-propylimidazole shows the best synergistic effect with KHIs. The synergistic effect between 2-propylimidazole and KHIs is mainly reflected in two aspects. On the one hand, the adsorption of 2-propylimidazole molecules on the hydrate surface hinders the formation of hydrate. On the other hand, 2-propylimidazole molecules can promote the formation of methane bubbles and reduce the driving force for the formation of methane hydrates. Our research further expands the application of imidazole reagents in the prevention and control of hydrates, which is beneficial to enhance the commercial application of KHIs.