Session: 11-07-01 Petroleum Production: Offshore Systems and Subsea Operations

Submission Number: 156554

Numerical Simulation Study on Flow Aggregation Characteristics of Hydrate Slurry in Z-Shaped Pipeline 

The distribution and deposition of natural gas hydrates within deep-sea subsea pipelines are critical to ensuring flow assurance and safety. Controlling hydrate flow as a slurry to mitigate the risk of hydrate blockage is a primary strategy. Current hydrate flow simulations based on the PBM (Population Balance Model) predominantly focus on straight pipeline systems, with limited attention given to nucleation and deposition behaviors in pipelines with specialized geometries. By developing a hydrate flow model within a Z-shaped pipeline, this study incorporates processes such as uneven liquid film distribution on pipe walls, hydrate nucleation, gas-liquid mass transfer, particle adhesion and aggregation, and dynamic deposition. This comprehensive approach enables the simulation of the entire process of hydrate formation, aggregation, fragmentation, and deposition. Simulations were conducted in a Z-shaped pipeline to investigate the effects of flow velocity, hydrate particle size, and hydrate volume fraction on the slurry flow characteristics. Results indicate that the hydrate particle velocity exhibits an approximately symmetrical distribution across the pipeline outlet in the transverse direction. The particle size distribution of hydrates in the slurry flow field within the pipeline follows a log-normal pattern. Increasing the hydrate volume fraction accelerates particle aggregation. A significant risk is posed by the formation of high-concentration particle aggregation zones at the bottom of the downstream bend of the pipeline.

Presenting Author: En Li China University of Petroleum (East China)

Presenting Author Biography: En Li received the M.S. degree in Petroleum and Natural Gas Engineering from Yangtze University, Wuhan, China, in 2023. He is currently pursuing a Ph.D. degree in Engineering with the College of Petroleum Engineering, China University of Petroleum (East China), Qingdao, China. His research interests include flow assurance with hydrates and offshore oil drilling and production technology.