Characterization\nand Application of Surface-Modified\nFe<sub>3</sub>O<sub>4</sub> Nanoparticles as Recyclable Dispersants\nfor Gas Hydrate Slurry Transportability

Gas hydrate formation and accumulation in flowlines pose\nsignificant\nchallenges to oil and gas production. To mitigate these issues, low-dosage\nhydrate inhibitors, such as antiagglomerants, are used to maintain\nhydrate particles in a slurry form and prevent their agglomeration.\nRecently, functional nanoparticles have emerged as a promising alternative\ndispersant. These nanoparticles can assemble at the oil–water\ninterface, creating a physical barrier that prevents the agglomeration\nof hydrate particles. Unlike traditional molecular additives, nanoparticles\noffer several advantages: they are environmentally friendly, conveniently\nrecyclable, and potentially cost-effective. In this study, 50 nm commercial\nFe<sub>3</sub>O<sub>4</sub> nanoparticles were modified with silane\nto tune their hydrophobicity and tested as particulate hydrate slurry\ndispersants in the rock-flow cell, an apparatus that can evaluate\nflow risk under controlled shear, temperature, and pressure conditions.\nThe performance of the nanoparticles with different hydrophobicities\nand dosages was directly correlated with the morphology of hydrate\ndistribution at steady state. A hydrate slurry phase map was used\nto assess the performance of the nanoparticles in mitigating hydrate\nagglomeration. Additionally, the reusability of the nanoparticles\nwas also tested by recycling them with a magnet and repeating the\nsame experiment to evaluate their performance postrecycling. This\nstudy demonstrates the potential of functional Fe<sub>3</sub>O<sub>4</sub> nanoparticles as effective dispersants for enhancing gas\nhydrate transportability in slurry form and the associated benefit\nwith their reusability.