Critical Deposition Velocity of Hydrate Particles in Undulating Section of Gas Pipeline

According to the deposition law of hydrate particles in the deepwater undulating pipe, this paper analyzed the stress of hydrate particles in the undulating pipe, established the force model and critical deposition velocity model of hydrate particles. Based on the analysis of individual hydrate particle, the coalescence between hydrate particles was analyzed, and the force and critical sedimentation flow rate of hydrate particles after coalescence were studied. Based on the critical deposition velocity model of hydrate particle, the effects of hydrate particle diameter, gas density, pipe wall roughness and different pipe inclination on the critical deposition velocity of hydrate particles were analyzed. The results show that the critical deposition velocity of hydrate particle decreases with the increase of hydrate particle size; With the increase of fluid density in the pipe, the critical deposition velocity of hydrate particle decreases; The critical velocity of hydrate particle increases with the increase of pipeline roughness; In the upwardly inclined pipe section, the critical deposition velocity of hydrate particle first increases and then decreases with the increase of pipe inclination; In the downwardly inclined pipeline, with the increase of the inclination angle of the pipeline, the critical deposition velocity of hydrate particle gradually decreases, and the hydrate particles are more easily separated from the pipe wall, so it is easier to form hydrate deposition and blockage at the connection between the downwardly inclined pipeline section and the straight pipeline section.