Modeling the micromechanical interactions between clathrate hydrate particles and water droplets with reducing liquid volume

- Hydrate film/shell grows along the water-hydrocarbon interface.
- Equations were developed for describing hydrate growth on liquid bridge surface.
- Model was proposed for simulating the interactions by considering hydrate formation.
- Effects of hydrate formation rate, water volume on adhesion force were discussed.

The micromechanical interactions between hydrate particles and water droplets play an important role in determining hydrate agglomeration, which is a crucial cause of hydrate blockages/bedding in deepwater gas-oil flowlines. The amount of hydrate converted from water droplet during the interaction between hydrate particles and water droplets led to the reduction in liquid volume, which would significantly affect the interaction forces. The existing classic pendular liquid bridge model with fixed liquid volume is not adequate for this unique case. In this study, a modified pendular liquid bridge model has been developed by considering the conversion of hydrate from liquid droplet. Parabolic approximation and a rupture criterion are proposed to determine the liquid bridge profile and rupture distance, respectively. On the basis of experimental observations, the capillary force model between two plates is applied to predict the interaction forces. It is found that the evolution of the profile of bridge (including the hydrate coating section and the pure liquid section) can be predicted with a satisfactory accuracy. Subsequently, it ensures the good agreement between the measured and predicted interaction forces. The profile of the liquid bridge becomes unstable just before the rupture of the liquid bridge, resulting in a large deviation between the experimental results and the model predictions. The proposed model can be successfully used for investigating the effects of different factors, such as contact area and hydrate formation rate, on the interaction behavior/forces, which could help to provide new and critical insights into the hydrate agglomeration process. The developed models contribute a significant progress in existing models development on hydrate agglomeration, and thus could provide a more accurate evaluation of hydrate formation risk in gas-oil flowlines.