Polymers of N-(Pyrrolidin-1-yl)methacrylamide as High Cloud Point Kinetic Hydrate Inhibitors

Abstract

Formation of gas hydrates is a major problem in flowlines where gas and water are transported together, and can lead to blockages, downtime, economic losses, and potential accidents. One way of preventing gas hydrates from forming is by injection of kinetic hydrate inhibitors (KHIs). KHIs are typically water-soluble polymers, often containing amide pendant groups. Based on our previous work on high cloud point polymers of N,N-dimethylhydrazidoacrylamide (polyDMHAM) and N,N-dimethylhydrazidomethacrylamide (polyDMHMAM), we have now synthesized a series of N-(pyrrolidin-1-yl)methacrylamide polymers (polyNPyMA) which contains a pyrrolidine-substituted hydrazido pendant group. These polymers show improvement on all previous hydrazido polymers as they exhibit improved KHI performance while having no cloud point in deionized water or 7 wt % aqueous NaCl up to 95 °C. Their performance as KHIs have been investigated using a high-pressure gas hydrate rocker rig at a pressure of 76 bar using a structure II forming n...