Optimizing the Kinetic Hydrate Inhibition Performance ofN-Alkyl-N-vinylamide Copolymers

Abstract

The generation of gas hydrates in gas and multiphase flowlines can cause blockages, leading to downtime, economic losses, and even potential accidents. Injecting kinetic hydrate inhibitors (KHIs) is an effective way to prevent gas hydrate formation. Most KHI formulations are built around water-soluble polymers containing amide groups. On the basis of past work on N-alkyl-N-vinylamide polymers from our group, we have now been able to become much closer to designing the optimum KHI for this class of polymers. In this study, we have synthesized four N-alkyl-N-vinylamide monomers, where the alkyl group is n-propyl, isopropyl, n-butyl, and isobutyl. These have been copolymerized successfully with N-methyl-N-vinylacetamide and N-vinylformamide to form a series of copolymers with low molecular weights. We have investigated their KHI performance using a slow constant cooling method with a synthetic natural gas mixture in high-pressure rocker cells at 76 bar. All of the new N-vinylamide copolymers show good KHI pe...