Study of Anti-Agglomerant Low Dosage Hydrate Inhibitor Performance

摘要

Gas hydrates can form in subsea oil and gas flowlines, where the depths of seawater and ocean conditionsrnprovide the thermodynamic environment for hydrate stability. Hydrates present a major flow assurancernproblem due to the relatively fast timescales at which they can form, grow/agglomerate, and plug a flowline.rnThe common strategy for preventing hydrate formation uses thermodynamic inhibitors (THIs). However,rnTHIs can be cost prohibitive or impractical as the water content in the flowline and its seawater depthrnincreases. Therefore, there is growing interest in the use of alternative hydrate management strategies,rnsuch as the injection of low dosage hydrate inhibitors (LDHIs), which are active at considerably lowerrnconcentrations than THIs (e.g. 2 vol.% of LDHI versus 50 vol.% of THI). Anti-agglomerants (AAs) arerna type of LDHI that prevent agglomeration and allow hydrates to flow as a slurry in oil and gas subsearnflowlines. Before field deployment, AAs are screened and selected using laboratory set-ups, mimickingrnfield conditions, in order to evaluate their performance and determine the effective dosage. Current hydraternagglomeration characterization methods implemented in the industry are non-uniform and qualitative, whichrncan lead to conservative recommendations.