Hydrate predictions on the China-Russia eastern gas pipeline during the pipeline goes into production

The China-Russia eastern gas pipeline has the characteristics of large pipe diameter and high pressure. During the pipeline goes into production, the temperature along the pipeline was low, and the conditions of low temperature and high pressure brought the risk of hydrate formation. Based on the multiphase flow theory and the CSMHyK hydrate growth kinetic model, this paper studied the hydrate formation region, the amount of hydrate formed and the influence of hydrate formation on the temperature drop and pressure drop of the China-Russia eastern gas pipeline in the first winter the pipeline goes into production. The results show that in the first winter the pipeline goes into production when the water content is more than 150 mg/kg the hydrate formation risk exists in the pipeline. Hydrate accumulates mainly in the ascending part of the low-lying pipe section, and the greater the height difference of the pipe section, the more hydrate accumulation. In the stage of mass hydrate formation, the temperature in the pipeline will rise due to hydrate formation, but when hydrate growth reaches equilibrium, the temperature in the pipeline is mainly controlled by the external soil temperature. In addition, a large amount of hydrate accumulation will generate a throttling effect, which will lead to increased temperature drop and pressure drop of the pipeline. When the water content is 350 mg/kg, the maximum additional pressure drop generated by hydrate aggregation is 2.27MPa.