EFFECTIVE KINETIC INHIBITORS FOR NATURAL-GAS HYDRATES

Kinetic inhibition is a new means of preventing flow channel blockage by natural gas hydrates. In kinetic inhibition the system is allowed t o exist within the hydrate thermodynamic stability zone, so that small crystals are stabilized without agglomerating to larger hydrate masse s which plug pipelines. A hydrate formation mechanism is reviewed to s uggest the new inhibition method. Macroscopic experiments on two appar atuses are presented for the best kinetic inhibitors among approximate ly 1500 chemicals. Pressure, concentration, and salinity limitations w ere measured for the three best kinetic inhibitors: poly(N-vinylcaprol actam) (PVCAP), N-vinylpyrrolidone/N-vinylcaprolactam/N, N-dimethylami noethyl-methacrylate (VC-713), and N-vinylpyrrolidone-co-N-vinylcaprol actam (VP/VC). Field tests have verified the laboratory research.