Environmentally friendly corrosion inhibitor
View Patent ↗Disclosed and claimed is a method of inhibiting corrosion of a surface in contact with a corrosive environment encountered in oil and gas operations. The method includes contacting the surface with a composition comprising a quaternary nitrogen-containing corrosion inhibitor having the following general formula. The composition is preferably adherent to standards for environmental friendliness but has equal applicability in formulations that include conventional corrosion inhibitors.
1. A method of inhibiting corrosion of a surface in contact with a corrosive environment encountered in oil and gas operations, the method comprising: contacting the surface with a composition comprising a quaternary nitrogen-containing corrosion inhibitor having the general formula:
wherein: (i) n is an integer from 1 to 4; (ii) R 1 , R 2 , R 3 , R 4 , and R 5 are each independently selected from —C(═O)NH(R 8 ), tetrazolyl, —N(H)C(═O)R 8 , —CO 2 H, —CO 2 R 6 , —C(═O)NH 2 , and —C(═O)NR 7 R 8 wherein R 6 is a C 1 -C 8 alkyl or phenyl, R 7 is H or a C 1 -C 4 alkyl, R 8 is H or a C 1 -C 4 alkyl, W is 1 or 2, and X is 1 or 2; (iii) Y is selected from napthyl, benzyl, anthracyl, phenanthrinyl, substituted napthyl, substituted benzyl, substituted anthracyl, substituted phenanthrinyl, and combinations thereof; and (iv) X − is a counterion with a charge sufficient to balance the positive charge on the parent compound of the general formula; and
wherein the composition retains dispersibility in an acidic environment.
2. The method of claim 1 , wherein said substituent groups in the substituted napthyl, substituted benzyl, substituted anthracyl, and substituted phenanthrinyl comprise groups selected from: cyano, amino, aminoalkyl, cycloalkyl, aryl, arylalkyl, and combinations thereof.
3. The method of claim 1 , wherein Y is selected from: substituted benzyl, substituted naphthalenyl, substituted anthracyl, substituted phenanthrinyl, and combinations thereof.
4. The method of claim 1 , wherein said substituent groups in the substituted napthyl, substituted benzyl, substituted anthracyl, and substituted phenanthrinyl comprise groups selected from: alkyl, alkoxy, hydroxyl, ester, and combinations thereof.
5. The method of claim 1 , wherein Y is selected from: benzyl, naphthyl, anthracyl, phenanthrinyl, and combinations thereof.
6. A method of inhibiting corrosion of a surface in contact with a corrosive environment encountered in oil and gas operations, the method comprising: contacting the surface with a composition comprising a quaternary nitrogen-containing corrosion inhibitor selected from at least one of the structures:
and wherein the composition retains dispersibility in an acidic environment.
7. The method of claim 1 , wherein the composition further comprises a solvent selected from: polar aprotic solvents, esters, aromatic solvents, terpenoids, terpenes, ionic solvents, acetals, alcohols, and combinations thereof.
8. The method of claim 7 , wherein the solvent is selected from: glycerine; ethyl lactate; propylene glycol; 1,3-propanediol; ethylene glycol; water; and combinations thereof.
9. The method of claim 1 , wherein the composition further comprises at least one additional component which is a surfactant.
10. The method of claim 1 , wherein the composition further comprises at least one intensifier.
11. The method of claim 10 , wherein the intensifier is selected from: formic acid, formic acid compounds, α, β -unsaturated aldehydes, iodide salts, acetylenic alcohols, and combinations thereof.
12. The method of claim 1 , wherein the composition comprises from about 0.1 to about 80% by weight of the quaternary nitrogen-containing corrosion inhibitor.
13. The method of claim 8 , wherein the composition comprises from about 1 to about 70% weight percent of the solvent.
14. The method of claim 9 , wherein the composition comprises from about 0.01 to about 30% by weight of the surfactant.
15. The method of claim 11 , wherein the composition comprises from about 0.1 to about 60% weight percent of the intensifier.
16. The method of claim 1 , wherein the quaternary nitrogen-containing corrosion inhibitor comprises at least one North Sea criterion selected from: (i) a biodegradation rate of greater than 60%, (ii) Log P ow of less than 3; (iii) acute aquatic toxicity of greater than 10 mg/L; and combinations thereof.
17. The method of claim 1 , wherein the counterion is selected from at least one of the following: halides; hexafluorophosphates; nitrates; nitrites; acetates; bicarbonates; cyanides; perchlorates; hydroxides; sulfates; sulfites; mesylates; and combinations thereof.