LAUSR

Abstract Clathrate hydrate particle cohesion dominates agglomeration of hydrate particles in gas/oil pipelines, and the existence of a capillary bridge between hydrate particles was assumed to be the reason of hydrate particle cohesion. This assumption implied the cohesive force between hydrate particles were radius-dependent but without any experimental validations. The cohesive force between cyclopentane (CP) hydrate particles in liquid CP phase and the cohesive force between CH4/C2H6 gas hydrate particles in the gas phase were measured respectively by using micromechanical force apparatus, and the effects of particle size and annealing time on hydrate particle cohesion in different phases were investigated. The cohesive force between hydrate particles was found independent of particle size in liquid CP phase but was linearly correlated with the effective radius of the hydrate particle pair in the gas phase. Long annealing time decreased cohesive force measured in liquid CP phase but had no significant effect on the cohesion of hydrate particle in the gas phase. A possible mechanism was therefore proposed to interpret hydrate particle cohesion in different phases: The cohesion of hydrate particles in liquid hydrocarbon was dominated by the sintering of asperities, but hydrate particle cohesion in gaseous hydrocarbons was still caused by the existence of capillary bridge.