Hydrate formation and agglomeration in Pickering emulsions stabilized by hydrophilic and hydrophobic nano-CaCO3 particles

• Published in: Petroleum science Vol. 22; no. 9; pp. 3817 - 3829
• Main Authors: Guo, Dong-Dong, Ou, Wen-Jia, Zhang, Yun-Hong, Zhu, Heng-Yin, Din, Shahab Ud, Wang, Ren, Ning, Fu-Long
• Format: Journal Article
• Language: English
• Published: Beijing Elsevier B.V 01.09.2025; KeAi Publishing Communications Ltd
• Subjects: Calcium carbonate; Crude oil; Deep water; Deepwater drilling; Drilling fluids; Emulsions; Fluids; Gas hydrate; Gas hydrates; Growth rate; Hydrates; Hydrophilicity; Hydrophilicity and hydrophobicity; Hydrophobicity; Inhibition effect; Interface stability; Kinetics; Multiphase flow; Nano-CaCO3 particles; Nanoparticles; Natural gas; Oil and gas industries; Oil and gas industry; Oil and gas operations; Oil-water interface; Particle size; Petroleum engineering; Petroleum industry; Pickering emulsion; Surfactants; Temperature; Water; Gas hydrate; Inhibition effect; Pickering emulsion; Hydrophilicity and hydrophobicity; Nano-CaCO3 particles
• ISSN: 1995-8226; 1672-5107; 1995-8226
• DOI: 10.1016/j.petsci.2025.08.022

The stability of oil-dominated emulsions, including oil-based drilling fluids and crude oils, is crucial for mitigating gas hydrate risks in the petroleum and natural gas industries. Nanoparticles can stabilize oil-water systems (Pickering emulsions) by residing at the oil-water interface. However, their effects on the kinetics of hydrate formation in these systems remain unclear. To address this, we experimentally investigated how hydrophilic and hydrophobic nano-CaCO3 influence CH4 hydrate formation within dynamic oil-water systems. A series of hydrate formation experiments were conducted with varying water cuts and different concentrations of nano-CaCO3 at a particle size of 20 nm, under 3 °C and 6 MPa. The induction time, hydrate formation volume, and hydrate growth rate were measured and calculated. The results indicate that hydrophilic nano-CaCO3 generally inhibits hydrate formation, particularly at high water cuts, while hydrophobic nano-CaCO3 can significantly inhibit or even prevent hydrate formation at low water cuts. Water cut strongly influences the kinetics of hydrate formation, and nanoparticle concentration also impacts the results, likely due to changes in oil-water interface stability caused by nanoparticle distribution. This study will offer valuable insights for designing deepwater oil-based drilling fluids using nanoparticles and ensuring safe multiphase flow in deepwater oil and gas operations.