METHOD FOR INHIBITING HYDRATE FORMATION

摘要

Clathrate hydrate formation in petroleum fluid streams is inhibited by adding water soluble polymers having N-vinyl amide or N-allyl amide units to the streams. Each N-vinyl amide and N-allyl amide unit has two substituent groups, R1 and R2, substituted on the nitrogen where R1 is a hydrogen or hydrocarbon group having one to six carbon atoms and zero to two heteroatoms selected from the group consisting of oxygen, nitrogen, and combinations thereof, where R2 is a hydrocarbon group having one to six carbon atoms and zero to two heteroatoms selected from the group consisting of oxygen, nitrogen, and combinations thereof, and where the sum total of carbon atoms in R1 and R2 is greater than or equal to one, but less than eight. Some preferred examples of such polymers include copolymers of N-vinyl amides and substituted acrylamides. Specific examples of such copolymers include, N-methyl-N-vinylacetamide (VIMA) copolymerized with acryloylpyrrolidine (APYD) or acryloylpiperidine (APID) and more preferably, VIMA copolymerized with N-substituted methacrylamides such as N-isopropylmethacrylamide (iPMAM) and methacryloylpyrrolidine (MAPYD).