The presence of unconverted water drops in bulk hydrocarbon is likely to bridge hydrate particles and cause hydrate agglomeration, leading to hydrate accumulation or bedding in oil and gas pipelines. The knowledge of the interaction forces between hydrate particles and water drops can provide critical insights into hydrate agglomeration as well as potential prevention strategies. At high subcooling, the frequent solidification of the capillary bridge between hydrate particles could significantly affect the interaction force. However, the existing classic pendular liquid bridge model with a fixed liquid volume is not adequate for this unique case. A new interaction force model is required. Based on the pendular liquid bridge model and hydrate shell theory, a modified interaction force model was developed by considering the solidification of capillary bridges. Furthermore, using a self-built micromechanical force apparatus, the cyclopentane (CyC5) hydrate−droplet adhesion forces at a temperature range from 0.5 to 6 °C were measured to verify the proposed model. The experiments suggest that as the temperature was increased from 0.5 to 6 °C, the adhesion forces first increased and then decreased. Solidification could enhance the strength of the already formed liquid bridge. However, at lower temperatures (0.5−3 °C), the quick solidification led to smaller particle/bridge initial contact areas and weaker adhesion forces. By accurately predicting the evolution of the capillary bridge shape/outline, the predicted adhesion forces agree well with the experimental measurements. This study can provide more insights into hydrate agglomeration. The proposed model is an important supplement to hydrate adhesion theory and could more accurately evaluate hydrate plug risks in gas−oil flowlines.

In order to explore the kinetic mechanism of hydrate formation in a system containing micron-sized SiO2 particles, this paper uses a high-pressure reactor device with stirring function to record changes in pressure, temperature and torque during the growth of hydrates through a data acquisition system, based on the conservation of mass in the system The principle and gas equation of state calculate the kinetic parameters of hydrate formation such as gas consumption in the reactor, hydrate formation rate and induction time, and analyze the influence of particle size and particle concentration on the kinetic characteristics of hydrate formation based on the experimental results. The experimental results show that the particle content has no obvious effect on the average growth rate of hydrate in the range of 1%-7%, but increasing the particle content can effectively reduce the hydration induction time; when the particle size is in the range of 2.5-85 μm, the larger the particle size, the shorter the hydrate induction time and the greater the hydrate growth rate.