Hydrate plug prevention by anti-agglomeration

Dispersing hydrates into a condensate phase by anti-agglomerants is an alternative to kinetic or thermodynamic inhibitors to prevent hydrate plug formation in a gas production pipeline. In this work, both commercially available surfactants and synthesized anti-agglomerants were tested in high-pressure apparatuses at typical pipeline conditions. Candidates from families of commercially available surfactants, chosen based on their hydrophilic-lipophilic balance (HLB), were tested in an H2O-hydrocarbon mixture of 30% water and 70% octane (volume). It was found that, at 3 wt% of the water mass with a synthetic natural gas, some commercial surfactants (Span 20, Span 40, Span 60, Span 80) could keep hydrate particles suspended in a range of condensate types and shear numbers at 4 degreesC and 8.27 MPa. However, a synthesized chemical dodecyl-2-(2-caprolactamyl) ethanamide was a more efficient dispersant at 0.75 wt% of the water mass. Both synthesized and commercial chemicals passed 5-day shut-in tests based upon torque measurements and visual hydrate observations. Flow-loop testing is needed to extend this work to field applications. (C) 2001 Elsevier Science Ltd. All rights reserved.