Interfacial Regulation of Hydrate Growth Pathways and Blockage Evolution under Oscillatory Conditions

Hydrate blockages remain major flow-assurance challenges in oil and gas transportation. In this work, interfacial regulation of hydrate growth pathways and blockage evolution were investigated by combining rocking-cell experiments with molecular simulations. The experimental results showed that the most severe hydrate-forming condition corresponded to a water cut of 60 vol % and an oscillation rate of 10 min-1. Under this condition, Luvicap-EG showed a clear concentration-dependent inhibition effect: increasing inhibitor concentration progressively reduced pressure decline and water conversion, significantly prolonged induction time, and lowered the gas-liquid interfacial tension. In addition, Luvicap-EG altered hydrate evolution from a blockage-forming to a dispersion-dominated pathway. Molecular simulations further showed that increasing periodic mechanical loading first induced cage distortion and strain accumulation and then caused fragmentation of the hydrate framework, providing a molecular-scale explanation for the slurry-like morphology observed experimentally at high oscillation rates. Simulations further showed that PVCap disrupted continuous hydrate growth and progressively reduced hydrate ordering with increasing concentration. These results show that Luvicap-EG regulates hydrate evolution through coupled effects on interfacial behavior, formation kinetics, and structural continuity, thereby redirecting the system from blockage-forming growth toward a structurally destabilized and dispersed state.