Inhibitors of top-of-line corrosion of pipelines conveying crudes from extraction of hydrocarbons
The invention relates to a composition for inhibiting corrosion of the upper part (or roof) of a pipeline for conveying wet hydrocarbons, i.e. hydrocarbons comprising a variable amount of water, said composition comprising at least one Amine 1 with vapor pressure greater than or equal to 10 mmHg, and at least one. Amine 2 with vapor pressure greater than or equal to 0.1 mmHg and strictly less than 10 mmHg. The invention also relates to the use of such a composition, and also to the method of inhibiting top-of-line corrosion employing said inhibitor composition.
1. Composition for inhibiting top-of-line corrosion, comprising:
from 1% to 30% by weight of at least one first amine (Amine 1) with vapour pressure greater than or equal to 10 mmHg (1.33 kPa), measured at 20° C.;
from 5% to 50% by weight of at least one second amine (Amine 2) with vapour pressure greater than or equal to 0.1 mmHg (≥13.3 Pa) and less than 10 mmHg (<1.33 kPa), measured at 20° C.;
from 5% to 20% by weight of at least one sulphur-containing additive, selected from mercapto acids and mercapto-alcohols;
from 0 to 60% by weight of at least one alkanolamine; and
optionally at least one solvent, in a sufficient quantity (q.s.) to reach 100%.
2. Composition according to claim 1 , wherein Amine 1 corresponds to the following formula (1):
wherein:
R 1a is selected from linear or branched, saturated or partially or fully unsaturated hydrocarbon chains, comprising from 1 to 6 carbon atoms, and optionally one or more oxygen atoms in the chain, and
R 1b and R 1c , which may be identical or different, are selected, independently of one another, from a hydrogen atom and linear, branched or cyclic, saturated or partially or fully unsaturated hydrocarbon chains, comprising from 1 to 6 carbon atoms, and optionally one or more heteroatoms selected from oxygen, nitrogen and sulphur, in the chain.
3. Composition according to claim 1 , wherein Amine 1 is selected from MOPA (methoxy-3-propylamine) and EDIPA (N,N-diisopropylethylamine).
4. Composition according to claim 1 , wherein Amine 2 corresponds to the following formula (2):
wherein:
R 2a is selected from linear, branched or cyclic, saturated or partially or fully unsaturated hydrocarbon chains, comprising 1 to 12 carbon atoms, and optionally one or more heteroatoms selected from oxygen, nitrogen and sulphur, in the chain, and
R 2b and R 2c , which may be identical or different, are selected, independently of one another, from a hydrogen atom and linear, branched or cyclic, saturated or partially or fully unsaturated hydrocarbon chains, comprising 1 to 12 carbon atoms.
5. Composition according to claim 1 , wherein Amine 2 is selected from octylamines, nonylamines, decylamines, undecylamines and dodecylamines.
6. Composition according to claim 1 , further comprising one or more other inhibitors for inhibiting other types of corrosion encountered in the area of extraction of hydrocarbons.
7. Method of inhibiting top-of-line corrosion of a hydrocarbon pipeline in which gas, crude oil, gas and crude oil circulate, mixed with a variable amount of water, comprising injecting a composition according to claim 1 into the pipeline.
8. Method according to claim 7 , wherein the inhibitor composition is injected at a rate from 100 ppm to 10 000 ppm, expressed as the weight of the corrosion inhibiting composition per part by volume of corrosive fluids to be treated.
9. Method of inhibiting top-of-line corrosion of a pipeline conveying wet gas and/or wet multiphase crude oil, comprising a liquid phase flowing along the lower portion of the pipeline and a gas phase flowing along the upper portion of the pipeline, said method comprising at least one step of introducing, in continuous, batch or squeeze mode at least one corrosion inhibiting composition according to claim 1 into said pipeline.
10. Method according to claim 9 , wherein the inhibitor composition is injected at a rate from 100 ppm to 10 000 ppm, expressed as weight of the corrosion inhibiting composition per part by volume of corrosive fluids to be treated.
11. Method according to claim 9 , further comprising application of one or more physical treatments.
12. Composition according to claim 1 , wherein the composition comprises from 5% to 20% by weight of the at least one first amine (Amine 1) with vapour pressure greater than or equal to 10 mmHg (1.33 kPa), measured at 20° C.
13. Composition according to claim 1 , wherein the composition comprises from 15% to 45% by weight of the at least one second amine (Amine 2) with vapour pressure greater than or equal to 0.1 mmHg (≥13.3 Pa) and less than 10 mmHg (<1.33 kPa), measured at 20° C.
14. Composition according to claim 1 , wherein the at least one sulphur-containing additive is selected from the group consisting of mercapto-ethanol, mercapto-propanol, thioglycolic acid, mercatopropionic acid and mixtures thereof.
15. Composition according to claim 1 , wherein the composition comprises from 0 to 50% of the at least one alkanolamine.
16. Composition according to claim 1 , wherein Amine 2 is n-octylamine.
17. Composition according to claim 6 , wherein the one or more other inhibitor comprises a bottom-of-line corrosion inhibitor.
18. Method according to claim 7 , wherein the composition is injected continuously.
19. Method according to claim 9 , wherein the at least one corrosion inhibiting composition is introduced continuously.
20. Method according to claim 11 , wherein the one or more physical treatments comprise scraping.
21. Composition according to claim 1 , wherein the sulphur-containing additive comprises a mercapto-alcohol.
22. Composition according to claim 1 , which contains the alkanolamine.