ION PAIR AMPHIPHILES AS HYDRATE INHIBITORS
A method of inhibiting hydrates in a fluid comprising water and gas comprising adding to the fluid an effective hydrate-inhibiting amount of one or more ion-pair amphiphiles, wherein the ion-pair amphiphiles are composed of one or more cationic amphiphiles and one or more anionic amphiphiles.
1 . A method of inhibiting hydrates in a fluid comprising water, gas and optionally liquid hydrocarbon comprising treating the fluid with an effective hydrate-inhibiting amount of one or more ion-pair amphiphiles, wherein the ion-pair amphiphiles are composed of one or more cationic amphiphiles and one or more anionic amphiphiles, wherein said anionic amphiphile comprises at least one C 5 -C 25 alkyl or C 5 -C 25 alkenyl group.
2 . The method of claim 1 wherein the cationic amphiphiles are selected from the group consisting of compounds of formula
wherein R 1 , R 5 , R 7 , R 8 , R 12 , R 13 and R 17 are independently selected from C 1 -C 4 alkyl; R 2 , R 9 and R 14 are independently selected from C 1 -C 4 alkyl and arylalkyl; R 4 is C 1 -C 4 alkyl, C 5 -C 25 alkyl or C 5 -C 25 alkenyl; R 3 , R 6 , R 10 , R 11 , R 15 , R 16 and R 18 are independently selected from C 5 -C 25 alkyl and C 5 -C 25 alkenyl; R 25 and R 26 are independently selected from H, C 1 -C 25 alkyl and C 2 -C 25 alkenyl; L is absent, C 1 -C 5 alkylene or a group of formula —CH 2 CH(OH)CH 2 —; and n is 1 to about 1,000.
3 . The method of claim 1 wherein the cationic amphiphiles are selected from the group consisting of compounds of formula
wherein R 1 , R 5 and R 17 are independently selected from C 1 -C 4 alkyl; R 2 is C 1 -C 4 alkyl or arylalkyl; R 4 is C 1 -C 4 alkyl, C 5 -C 25 alkyl or C 5 -C 25 alkenyl; R 3 , R 6 and R 1 are independently selected from C 5 -C 25 alkyl and C 5 -C 25 alkenyl, and R 25 and R 26 are independently selected from H, C 1 -C 25 alkyl and C 2 -C 25 alkenyl.
4 . The method of claim 1 wherein the anionic amphiphile is selected from the group consisting of compounds of formula
wherein R 19 , R 20 , R 22 , R 23 , R 27 and R 24 are independently selected from C 5 -C 25 alkyl, C 5 -C 25 alkenyl; R 21 is H, C 1 -C 4 alkyl or arylalkyl; and M is absent or a group of formula C 1 -C 5 alkylene or a group of formula —CH 2 CH(OH)CH 2 —.
5 . The method of claim 1 wherein the cationic amphiphiles are selected from the group consisting of compounds of formula
wherein R 1 , R 5 and R 17 are independently selected from C 1 -C 4 alkyl; R 2 is C 1 -C 4 alkyl or arylalkyl; R 4 is C 1 -C 4 alkyl, C 5 -C 25 alkyl or C 5 -C 25 alkenyl; R 3 , R 6 and R 18 are independently selected from C 5 -C 25 alkyl and C 5 -C 25 alkenyl, and R 25 and R 26 are independently selected from H, C 1 -C 25 alkyl and C 2 -C 25 alkenyl and the anionic amphiphiles are selected from the group consisting of compounds of formula
wherein R 19 , R 20 and R 22 are independently selected from C 5 -C 25 alkyl, C 5 -C 25 alkenyl; and R 21 is H, C 1 -C 4 alkyl or arylalkyl.
6 . The method of claim 5 wherein R 1 , R 4 , R 5 and R 17 are C 1 -C 4 alkyl; R 3 , R 6 and R 18 are independently selected from C 8 -C 18 alkyl and C 8 -C 18 alkenyl; R 21 , R 25 and R 26 are H; and R 19 , R 20 and R 22 are independently selected from C 6 -C 18 alkyl and C 6 -C 18 alkenyl.
7 . The method of claim 6 wherein the ion pair amphiphile is prepared by reacting one or more cationic amphiphiles selected from the group consisting of benzyl-dodecyl-dimethylammonium chloride, 1-butyl-3-dodecyl-4.5-dihydro-3H-imidazol-1-ium chloride, hexadecyl-trimethylammonium bromide, dodecyl-dimethylamine, 1-butyl-4-nonyl-pyridinium bromide, dodecylamine and tributyl-hexadecylammonium bromide and one or more anionic amphiphiles selected from the group consisting of hexanoic acid, octadec-9-enoic acid, hexadecanoic acid, sulfuric acid monododecyl ester, phosphoric acid monododecyl ester, dodecanoic acid-2-hydroxy-3-phosphonooxy-propyl ester and sulfuric acid mono-(4-dodecyl-phenyl) ester.
8 . The method of claim 6 wherein the ion-pair amphipile is prepared by reacting benzyl dimethyl cocoamine with one or more anionic amphiphiles selected from tall oil fatty acid, stearic acid and oleic acid.
9 . The method of claim 7 wherein the ion-pair amphiphile is selected from 1:1 benzyl dimethyl cocoamine-tall oil fatty acid, 1:1 benzyl dimethyl cocoamine-stearic acid and 1:1 benzyl dimethyl cocoamine-tall oil fatty acid.
10 . The method of claim 1 wherein the ion-pair amphiphile is formulated prior to addition to the fluid.
11 . The method of claim 1 wherein the treating comprises the sequential or simultaneous addition of one or more cationic amphiphiles and one or more anionic amphiphiles to the fluid.
12 . The method of claim 1 further comprising adding one or more thermodynamic hydrate inhibitors, one or more kinetic hydrate inhibitors, or one or more anti-agglomerates, or a combination thereof to the fluid.
13 . The method of claim 1 further comprising adding one or more asphaltine inhibitors, paraffin inhibitors, corrosion inhibitors, emulsion breakers or scale inhibitors, or a combination thereof to the fluid.
14 . A composition comprising one or more ion-pair amphiphiles and one or more non aqueous solvents.
15 . The composition of claim 14 wherein the non-aqueous solvents are selected from the group consisting of aromatics, alcohols, esters, aliphatics, glycols, and mixtures thereof.
16 . The composition of claim 14 wherein the non-aqueous solvents are selected from the group consisting of diesel, heavy aromatic naphtha, fatty acid methyl esters, xylene, toluene, and mixtures thereof.
17 . The composition of claim 14 wherein the non-aqueous solvents are selected from the group consisting of methanol, ethanol isopropanol, 2-butoxyethanol, ethylene glycol and propylene glycol and mixtures thereof.
18 . A composition comprising one or more ion-pair amphiphiles in a mixture of one or more aqueous solvents and one or more non-aqueous solvents.
19 . A composition comprising one or more ion-pair amphiphiles and one or more aqueous solvents, wherein the aqueous solvents are selected from brine and seawater.