Effect of Monoethylene Glycol Injection in Hydrate Management
Abstract
The presence of hydrates in deep water oil-gas-field operations is a fairly frequent issue. It is very important to have a hydrate management strategy for normal operation. This work evaluates the optimum mass concentration of monoethylene glycol (MEG) in hydrate management for a deep-water operation condition. A simulation-based approach was adopted and OLGA Dynamic Multiphase flow simulator and Multiflash fluid model modelling package were used. A base model was initially developed and subsequently adjusted for different mass concentrations of 10, 20, 30, 40, 44, and 45 MEG. The results for the actual production with no inhibition, shows that at 2268.53ft along the pipeline that 6.74853 х10-5 volume fraction of hydrate was formed at a pressure and temperature of 318.196psia and 3.41765°F in the pipeline. It also reveals that hydrates were formed at the inlet section of the pipeline. For 10 mass percent of Monoethylene glycol added to the fluid system, 573.651ft and 1.21864х10-7 volume fraction of hydrate was formed in the pipeline. Hydrate was thermodynamically unstable up to 573.651ft along the pipeline. After the unstable section, 1.21864х10-7 volume fraction of hydrate was formed in the pipeline. Result shows that increase in the mass percent of the MEG increases the length of instability of the hydrate formation along the pipeline and increase in the mass concentration of the MEG decreases the volume fraction of hydrate formed in the pipeline. Results further reveal that 45 percent mass concentration of MEG inhibited hydrate formation in the gas mixture.
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