Effect of Bubbles Produced from Hydrate-Bearing Particle Dissociation on Particle Motion in Water

Abstract

Understanding the motion of natural gas hydrate-bearing particles in a pipeline is of great significance for developing natural gas exploitation technology. In this study, the effect of bubbles produced from hydrate dissociation on the particle settling characteristics and the drag coefficient were studied under different Reynolds numbers. In the experiment, two types of porous solid spherical particles, namely, silty clay and quartz, were used to study the settling of ordinary particles and hydrate-bearing particles using a customized experimental apparatus. The settling and dissociation of the particle in water and the motion of bubbles were captured using a high-speed camera. The results showed that the gas from the hydrate dissociation surrounded the particle, which caused the boundary layer at the particle surface to prematurely separate at the back end of the particle, thereby increasing the interaction forces between the particle and the water during motion. The influence of bubbles on the particle motion was closely related to the hydrate dissociation rate and the particle settling velocity. Moreover, a mathematical expression is provided to describe the entire process from sediment particles entering the water to hydrate dissociation. Furthermore, the dissociation rate of the hydrate-bearing sediment particle under water flow was obtained.

Virtual Special Issue of Recent Research Advances in China: Unconventional Gas

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