Abstract: An additive for inhibiting the formation of gas hydrates in connection with hydrocarbon production and transportation comprising the water-soluble polymers comprising structural elements of the formula wherein each R is independently H or C1-C5-alkyl; X is H, an alkaline or earth alkaline metal or a quaternary ammonium group; R1 is H or C1-C18-alkyl; and R2 is C1-C18-alkyl; and wherein the alkyl groups represented by R1 and R2 optionally carry a hydroxy or amino substituent; and, optionally, a minor proportion of structural elements of the formula  wherein R, R1, R2 and X may have the meaning as above, and Alk is a C1-C5-alkylene chain.

Abstract: An additive for inhibiting the formation of gas hydrates in connection with hydrocarbon production and transportation comprising the water-soluble polymers comprising structural elements of the formula wherein each R is independently H or C1-C5-alkyl; X is H, an alkaline or earth alkaline metal or a quaternary ammonium group; R1 is H or C1-C18-alkyl; and R2 is C1-C18-alkyl; and wherein the alkyl groups represented by R1 and R2 optionally carry a hydroxy or amino substituent; and, optionally, a minor proportion of structural elements of the formula wherein R, R1, R2 and X may have the meaning as above, and Alk is a C1-C5-alkylene chain.

Abstract: The instant invention relates to the use of water-soluble polymers comprising structural elements of the formula 1

Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is disclosed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitor used for practicing the method is selected from the family of substantially water soluble copolymers formed from N-methyl-N-vinylacetamide (VIMA) and one of three comonomers, vinylpyrrolidone (VP), vinylpiperidone (VPip), or vinylcaprolactam (VCap). VIMA/VCap is the preferred copolymer. These copolymers may be used alone or in combination with each other or other hydrate inhibitors. Preferably, a solvent, such as water, brine, alcohol, or mixtures thereof, is used to produce an inhibitor solution or mixture to facilitate treatment of the petroleum fluid stream.