Carbamate Polymers as Kinetic Hydrate Inhibitors

摘要

Formation of gas hydrates is a problem in the petroleum industry,-where the gas hydrates can cause blockage of the flowlines. Kinetic hydrate inhibitors (KHIs) are water-soluble polymers that are used to prevent gas hydrate blockages, and they have been used in the field successfully. In this paper we present the first KM performance results of a series of polymers containing pendant carbamate groups, poly(hydroxyl-N-alkylcarbamate)s. Similar polymers have been investigated as KHIs before, some of which have been commercialized. Hydroxyalkylcarbamates with varying alkyl pendant groups from methyl to isobutyl are reported. It was found that increasing the pendant alkyl chain and branching gave increasing KHI performance; however, the polymer also became significantly less soluble in water or had a very low cloud point temperature (T-o). Both solubility and T-Cl were slightly improved by copolymerization, and we found that the copolymer with pendant iso-butyl- and methylcarbamate 2:1 and 3:1 gave the best results of average T-o = 8.5 and 8.4 degrees C, respectively. A copolymer of 2.5:1 with pendant iso-butyl- and methylcarbamate was also investigated at concentrations ranging from 1000 to 7000 ppm, where the increased polymer concentration showed increasing KHI performance.