Flow characteristics and morphology of hydrate slurry formed from (natural gas+diesel oil/condensate oil+water) system containing anti-agglomerant

• Published in: Chemical engineering science 2012-12, Vol.84, p.333-344
• Main Authors: Peng, Bao-Zi, Chen, Jun, Sun, Chang-Yu, Dandekar, Abhijit, Guo, Shao-Hui, Liu, Bei, Mu, Liang, Yang, Lan-Ying, Li, Wen-Zhi, Chen, Guang-Jin
• Format: Article
• Language: English
• Subjects: Anti-agglomerant; Applied sciences; Chemical engineering; diesel fuel; Exact sciences and technology; Flow characteristics; Fluid dynamics; Fluid flow; Fluids; Hydrate; Hydrates; Morphology; Non-Newtonian fluids; oils; pipelines; Rheology; Slurries; viscosity; Volume fraction
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2012.08.030

The performance of a new kind of anti-agglomerant was evaluated on preventing hydrate plug in oil and gas pipelines using a flow loop device where hydrate slurries were formed from (diesel oil/condensate oil+water) dispersed system. The flow characteristics, shut down/restart behavior, and morphology of hydrate slurries were investigated experimentally at different water cut. The experimental results show that the adopted anti-agglomerant can disperse hydrate particles in fluid phase apparently. The formed hydrate slurries can safely flow and be easily restarted even though the initial water cut is upto 30.0 vol%. The rheology of hydrate slurries was analyzed based on the power-law fluid assumption and the rheology parameters and apparent viscosity were determined at different hydrate volume fraction. The analyzed results show that hydrate slurry exhibits shear-thinning behavior and belongs to pseudoplastic fluid. Its non-Newtonian behavior becomes more obvious with increasing hydrate volume fraction in fluid phase. The authors believe that the results presented in this paper are of key significance from flow assurance standpoint. ▸ A new kind of anti-agglomerant was adopted to prevent hydrate and wax plugging. ▸ The hydrate slurry is a dispersion system rather than an emulsion. ▸ The morphology of hydrate slurry can be kept at subcooling of 26 K. ▸ Hydrate slurry exhibits shear-thinning behavior and belongs to pseudoplastic fluid. ▸ Non-Newtonian behavior becomes obvious with increasing hydrate volume fraction.