Controlling Hydrate Formation and Agglomeration in Oil–Water Emulsions with Leucine and Nonionic Surfactants

In the development of deepwater clean energy, the formation and aggregation of hydrates pose serious safety risks to pipeline operations. Preventing hydrate aggregation is one of the effective strategies for reducing operational risks in deep-sea oil and gas pipelines. This study investigates the hydrate formation and antiaggregation performance of nonionic surfactants (Span80 and Tween80) in oil–water emulsion in the presence of Leucine. The results indicate that compared to the single Leucine system, the composite system can simultaneously inhibit hydrate formation and particle aggregation. Among these, the Leucine + 0.2 wt % Span80 binary composite system exhibits the best antiaggregation effect, while the Leucine + Tween80 system shows the worst antiaggregation effect. Notably, when Tween80 was introduced to form a ternary system of Leucine + Span80 + Tween80, although the hydrate induction time was prolonged, the final hydrate formation was significantly increased compared to the Span80 binary system, leading to weakened antiagglomeration effects. This phenomenon indicates that Span80 plays a key role in the binary system, while the addition of Tween80 may alter the synergistic effects of the system. Additionally, this study observed the experimental phenomena to clarify the aggregation mechanism of hydrates under the three systems. This work has important reference value for the formation of hydrates in oil–water emulsion systems under low-temperature and high-pressure conditions, as well as for ensuring the safe flow of oil and gas pipelines in the future.