Characterization and Application of Surface-Modified Fe3O4 Nanoparticles as Recyclable Dispersants for Gas Hydrate Slurry Transportability

Abstract

Gas hydrate formation and accumulation in flowlines pose significant challenges to oil and gas production. To mitigate these issues, low-dosage hydrate inhibitors, such as antiagglomerants, are used to maintain hydrate particles in a slurry form and prevent their agglomeration. Recently, functional nanoparticles have emerged as a promising alternative dispersant. These nanoparticles can assemble at the oil–water interface, creating a physical barrier that prevents the agglomeration of hydrate particles. Unlike traditional molecular additives, nanoparticles offer several advantages: they are environmentally friendly, conveniently recyclable, and potentially cost-effective. In this study, 50 nm commercial Fe₃O₄ nanoparticles were modified with silane to tune their hydrophobicity and tested as particulate hydrate slurry dispersants in the rock-flow cell, an apparatus that can evaluate flow risk under controlled shear, temperature, and pressure conditions. The performance of the nanoparticles with different hydrophobicities and dosages was directly correlated with the morphology of hydrate distribution at steady state. A hydrate slurry phase map was used to assess the performance of the nanoparticles in mitigating hydrate agglomeration. Additionally, the reusability of the nanoparticles was also tested by recycling them with a magnet and repeating the same experiment to evaluate their performance postrecycling. This study demonstrates the potential of functional Fe₃O₄ nanoparticles as effective dispersants for enhancing gas hydrate transportability in slurry form and the associated benefit with their reusability.