Direct measurements of the interactions between methane hydrate particle-particle/droplet in high pressure gas phase

Hydrate particle agglomeration is the critical process of hydrate blocks the pipeline. However, the microscopic mechanism of hydrate agglomeration under high pressure is still unclear. In this study, the interactions between methane hydrate particle-particle/droplet in high pressure gas phase were initially measured using a custom-built high-pressure micromechanical force device (HP-MMF). Moreover, the effects of subcooling, annealing time, and contact time on the interaction forces were examined. The results suggest that the hydrate particle-particle cohesion forces are in the order of x 10 mN.m(-1), which increases with the contact time and decreases with the annealing time and subcooling. The reason is due to the change of these factors on the volume of the quasi-liquid layer (QLL) and the morphology of the particle. Compared with the cohesion forces of hydrate particle-particle, the adhesion forces between hydrate particle and water droplet are much stronger, and the force ranges from x 10(2) mN.m(-1) to x 10(3) mN.m(-1). The adhesion forces are also the function of subcooling and contact time. The increase in subcooling and contact time leads to higher water conversion rate in the liquid bridge. Consequently, the dominant mechanism of the interaction changes from liquid bridge capillary force to the strong tensile strength of the hydrate gradually. This study presents the primary investigation of methane hydrate particle interaction forces, which can offer insights into understanding the agglomeration mechanism of hydrate in the gas pipeline. Furthermore, the obtained interaction forces can supply basic data for evaluating the hydrate plugging risk.