Method of sequentially forming anti-corrosive coatings

Abstract

Improved methods for the anti-corrosion treatment of oil or gas recovery or conveying equipment are provided, wherein the individual components of an epoxy/curing agent anti-corrosion system are sequentially applied. Preferably, a liquid epoxy dispersion is first contacted with metal surfaces to be treated, followed after a period of time by a liquid curing agent dispersion. Sequential and time-delayed application of the system components allows treatment of very long pipelines or deep producing wells.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of steps involved in the anti-corrosion treatment of an oil or gas pipeline in accordance with the invention; and

FIG. 2 is a schematic representation of a producing oil well and illustrating the steps involved in the anti-corrosion treatment of the well.

Claims

1. A method of treating metallic surfaces of oil or gas recovery or conveying equipment, comprising the steps of: providing an anti-corrosion system including separate quantities of a first component including an epoxy resin active ingredient in a first compatible dispersant, and a second component including a curing agent active ingredient for the epoxy resin in a second compatible dispersant;initially contacting said metallic surfaces with one of said first and second components and causing the corresponding active ingredient to at least partially coat said metallic surfaces;passing a fluid separate from said first and second components over said at least partially coated metallic surfaces, said fluid selected from the group consisting of oil, natural gas, process water, and mixtures thereof; andafter said initial contacting and fluid-passing steps, subsequently contacting said at least partially coated metallic surfaces with the other of said first and second components, and causing the active ingredients of said components to react with each other and generate an anti-corrosion layer.

2. The method of claim 1, including the step of initially contacting said metallic surfaces with said first component, and thereafter contacting the at least partially coated metallic surfaces with said second component.

3. The method of claim 1, said first and second dispersants being the same.

4. The method of claim 3, said first and second dispersants each being selected from the group consisting of benzene, xylene, toluene, naptha, alcohol, and mixtures thereof.

5. The method of claim 4, said first and second dispersants each being aromatic naptha.

6. The method of claim 1, said first component including from about 10-50% by volume epoxy.

7. The method of claim 1, said second component including from about 10-50% by volume curing agent.

8. The method of claim 1, said first and second components being individually injected into said equipment.

9. The method of claim 1, said curing agent selected from the group consisting of alkoxylated amines, imidazolines, and mixtures thereof.

10. The method of claim 9, said curing agent comprising an alkoxylated tallow amine having from about 2-15 moles of alkoxylate per mole of tallow amine.

11. (canceled)

12. The method of claim 1, there being a period of at least about 30 seconds between said contacting steps.

13. The method of claim 12, said period being from about 30 seconds-4 hours.

14. The method of claim 1, said equipment comprising an oil or gas pipeline, and said method further comprising the steps of: placing a first shiftable pig within said pipeline;performing said initial contacting step;placing a second shiftable pig within said pipeline, with said first component located between the first and second pigs;allowing oil or gas within said pipeline to pass behind said second pig;placing a third shiftable pig in said pipeline, with said oil or gas between said second and third pigs;performing said subsequent contacting step; andplacing a fourth shiftable pig in said pipeline, with said second component between the third and fourth pigs.

15. The method of claim 1, said equipment comprising an operating oil or gas well, said method comprising the steps of: initially injecting said first component into the casing of said well;driving said first component downwardly within said well casing by injection of said fluid behind said first component;thereafter injecting said second component into said well casing; anddriving said second component downwardly within said well casing by injection of additional fluid behind said second component.

16. A method of treating metallic surfaces of an oil or gas pipeline, comprising the steps of: providing an anti-corrosion system including separate quantities of a first component including an epoxy resin active ingredient in a first compatible dispersant, and a second component including a curing agent active ingredient for the epoxy resin in a second compatible dispersant;initially contacting said metallic surfaces with one of said first and second components and causing the corresponding active ingredient to at least partially coat said metallic surfaces;passing a fluid separate from said first and second components over said at least partially coated metallic surfaces; andafter said initial contacting and fluid-passing steps, subsequently contacting said at least partially coated metallic surfaces with the other of said first and second components, and causing the active ingredients of said components to react with each other and generate an anti-corrosion layer,said method further comprising the steps of— placing a first shiftable pig within said pipeline;performing said initial contacting step;placing a second shiftable pig within said pipeline, with said first component located between the first and second pigs;allowing oil or gas within said pipeline to pass behind said second pig;placing a third shiftable pig in said pipeline, with said oil or gas between said second and third pigs;performing said subsequent contacting step; andplacing a fourth shiftable pig in said pipeline, with said second component between the third and fourth pigs.

17. A method of treating metallic surfaces of oil or gas recovery or conveying equipment during use of the equipment or recovery or conveying oil or gas, comprising the steps of: providing an anti-corrosion system including separate quantities of a first component including an epoxy resin active ingredient in a first compatible dispersant, and a second component including a curring agent active ingredient for the epoxy resin in a second compatible dispersant;initially contacting said metallic surfaces with one of said first and second components and causing the corresponding active ingredient to at least partially coat said metallic surface;passing a fluid separate from said first and second components over said at least partially coated metallic surface; andafter said initial contacting and fluid-passing steps, subsequently contacting said at least partially coated metallic surfaces with the other of said first and second components, and causing the active ingredients of said components to react with each other and generate an anti-corrosion layer,said initial contacting, fluid-passing and subsequent contacting steps being carried out during use of said equipment when oil or gas is being recovered or conveyed.

18. The method of claim 17, including the step of initially contacting said metallic surfaces with said first component, and thereafter contacting the at least partially coated metallic surfaces with said second component.

19. The method of claim 17, said first and second dispersants being the same.

20. The method of claim 19, said first and second dispersants each being selected from the group consisting of benzene, xylene, toluene, naptha, alcohol, and mixtures thereof.

21. The method of claim 20, said first and second dispersants each being aromatic naptha.

22. The method of claim 17, said first component including from about 20-50% by volume epoxy.

23. The method of claim 17, said second component including from about 10-50% by volume curing agent.

24. The method of claim 17, said first and second components being individually injected into said equipment.

25. The method of claim 17, said curing agent selected from the group consisting of alkoxylated amines, imidazolines, and mixtures thereof.

26. The method of claim 25, said curring agent comprising an alkoxylated tallow amine having from about 2-15 moles of alkoxylate per mole of tallow amine.

27. The method of claim 17, said fluid selected from the group consisting of oil, nature gas, process water, and mixtures thereof.

28. The method of claim 17, there being a period of at least about 30 seconds between said contacting steps.

29. The method of claim 28, said period being from about 30 seconds-4 hours.

30. The method of claim 17, said equipment comprising an oil or gas pipeline, and said method further comprising the steps of: placing a first shiftable pig within said pipeline;performing said initial contacting step;placing a second shiftable pig within said pipeline, with said first component located between the first and second pigs;allowing oil or gas within said pipeline to pass behind said second pig;placing a third shiftable pig in said pipeline, with said oil or gas between said second and third pigs;performing said subsequent contacting step; and placing a fourth shiftable pig in said pipeline, with said second component between the third and fourth pigs.

31. The method of claim 17, said equipment comprising an operating oil or gas well, said method comprising the steps of: initially injecting said first component into the casing of said well;driving said first component downwardly within said well casing by injection of said fluid behind said first component;thereafter injecting said second component into said well casing; anddriving said second component downwardly within said well casing by injection of additional fluid behind said second component.