Hydrate prediction, prevention and control simulation at the initial stage of commissioning of China-Russia Eastern Gas Pipeline

In view of the large pipeline diameter and high pressure of China-Russia Eastern Gas Pipeline, as well as the location of the northern section in cold region, the high pressure and low temperature conditions at the initial stage of pipeline commissioning and operation may raise the risk of hydrate formation. Based on the multiphase flow theory and CSMHyK hydrate formation dynamics model, research was carried out on hydrate formatting area, amount of hydrate formation, degree of hydrate accumulation in the pipeline and hydrate control methods under winter operation conditions in the first year of commissioning of the pipeline. The results show that when the water content of the pipeline gas is more than 150 mg/kg, the pipeline is at a risk of hydrate formation. Hydrate formatted in the pipeline mainly accumulates in downstream of the low-lying pipeline section. The higher the elevation difference of the pipeline section, the more hydrate accumulates. The degree of hydrate accumulation in the pipeline is related to both the elevation difference of the upslope pipelines and the elevation difference and slope of the downslope pipelines in the low-lying pipeline section. When ethylene glycol is used as hydrate inhibitor with the injection mass fraction up to 50%, hydrate formation in China-Russia Eastern Gas Pipeline can be effectively prevented.