LOW DOSAGE HYDRATE INHIBITOR
A low dosage hydrate inhibitor blend and a method of treating a well fluid are provided. The low dosage inhibitor blend, which s used in the method, comprises a first cationic surfactant and a second cationic surfactant. For example, the combination of the first and second cationic surfactants in the low dosage inhibitor blend achieves a synergistic effect on the ability of the inhibitor blend to mitigate problems caused by the formation of gas hydrates in a well fluid.
1 . A low dosage hydrate inhibitor blend, comprising:
(a) a first cationic surfactant, wherein said first cationic surfactant has the structural formula (1), shown below:
wherein: R 1 is an alkyl group or an alkenyl group having from 5 to 22 carbon atoms, R 2 and R 3 are each an alkyl group having from 1 to 6 carbon atoms, R 4 is a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and X— is selected from the group of a carboxylate, an acrylate, a methacrylate, a halide, a phosphonate, a sulfate, a sulfonate, a hydroxide, a carbonate, or any combination thereof; and
(b) a second cationic surfactant, wherein said second cationic surfactant has the structural formula (2), shown below:
wherein: R 1 is an alkyl group or an alkenyl group having from 5 to 22 carbon atoms, R 2 and R 3 are each an alkyl group having from 1 to 6 carbon atoms, R 4 is a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and X— is selected from the group of a carboxylate, an acrylate, a methacrylate, a halide, a phosphonate, a sulfate, a sulfonate, a hydroxide, a carbonate, or any combination thereof.
2 . The low dosage hydrate inhibitor blend of claim 1 , wherein R 1 of formula (1) is an alkyl group having from 5 to 22 carbon atoms.
3 . The low dosage hydrate inhibitor blend of claim 1 , wherein R 2 and R 3 of formula (1) are each an alkyl group having from 1 to 4 carbon atoms.
4 . The low dosage hydrate inhibitor blend of claim 1 , wherein R 4 of formula (1) is a hydrogen atom or an alkyl group having from 1 to 2 carbon atoms.
5 . The low dosage hydrate inhibitor blend of claim 1 , wherein R 1 of formula (2) is an alkyl group having from 5 to 22 carbon atoms.
6 . The low dosage hydrate inhibitor blend of claim 1 , wherein R 2 and R 3 of formula (2) are each an alkyl group having from 1 to 4 carbon atoms.
7 . The low dosage hydrate inhibitor blend of claim 1 , wherein R 4 of formula (2) is a hydrogen atom or an alkyl group having from 1 to 2 carbon atoms.
8 . The low dosage hydrate inhibitor blend of claim 1 , wherein said inhibitor blend comprises in the range of from about 10% by weight to about 90% by weight of said first cationic surfactant, and in the range of from about 10% by weight to about 90% by weight of said second cationic surfactant, each weight percentage being based on the total weight of the inhibitor blend.
9 . A method of treating a well fluid, comprising:
combining a low dosage hydrate inhibitor blend with said well fluid, said low dosage inhibitor blend including:
(a) a first cationic surfactant, wherein said first cationic surfactant has the structural formula (1), shown below:
wherein: R 1 is an alkyl group or an alkenyl group having from 5 to 22 carbon atoms, R 2 and R 3 are each an alkyl group having from 1 to 6 carbon atoms, R 4 is a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and X— is selected from the group of a carboxylate, an acrylate, a methacrylate, a halide, a phosphonate, a sulfate, a sulfonate, a hydroxide, a carbonate, or any combination thereof; and
(b) a second cationic surfactant, wherein said second cationic surfactant has the structural formula (2), shown below:
wherein: R 1 is an alkyl group or an alkenyl group having from 5 to 22 carbon atoms, R 2 and R 3 are each an alkyl group having from 1 to 6 carbon atoms, R 4 is a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and X— is selected from the group of a carboxylate, an acrylate, a methacrylate, a halide, a phosphonate, a sulfate, a sulfonate, a hydroxide, a carbonate, or any combination thereof.
10 . The method of claim 9 , wherein R 1 of formula (1) is an alkyl group having from 5 to 22 carbon atoms.
11 . The method of claim 9 , wherein R 2 and R 3 of formula (1) are each an alkyl group having from 1 to 4 carbon atoms.
12 . The method of claim 9 , wherein R 4 of formula (1) is a hydrogen atom or an alkyl group having from 1 to 2 carbon atoms.
13 . The method of claim 9 , wherein R 1 of formula (2) is an alkyl group having from 5 to 22 carbon atoms.
14 . The method of claim 9 , wherein R 2 and R 3 of formula (2) are each an alkyl group having from 1 to 4 carbon atoms.
15 . The method of claim 9 , wherein R 4 of formula (2) is a hydrogen atom or an alkyl group having from 1 to 2 carbon atoms.
16 . The method of claim 9 , wherein said low dosage hydrate inhibitor blend comprises in the range of from about 10% by weight to about 90% by weight of said first cationic surfactant, and in the range of from about 10% by weight to about 90% by weight of said second cationic surfactant, each weight percentage being based on the total weight of said inhibitor blend.
17 . The method of claim 9 , wherein the well fluid includes a fluid produced from a well.
18 . The method of claim 9 , wherein the well fluid includes a hydrocarbon or a fluid that has or will come into contact with a hydrocarbon.
19 . The method of claim 9 , wherein said well fluid is a mixture of a liquid hydrocarbon and water, wherein the mixture has a water cut of greater than about 5%.
20 . The method of claim 9 , wherein the well fluid includes a mixture of a hydrocarbon and water, and wherein said water includes condensed water.
21 . The method of claim 9 , wherein the well fluid is associated with an oil and gas well production system.
22 . The method of claim 9 , wherein said low dosage hydrate inhibitor blend is combined with the well fluid using mixing equipment.