Coated products and use thereof in oil fields

• US 20020128157A1
• Filed: 03/07/2002
• Published: 09/12/2002
• Est. Priority Date: 05/31/1996
• Status: Active Grant

• Current Assignee: BP Exploration Operating Company Limited (BP PLC)
• Original Assignee: BP Exploration Operating Company Limited (BP PLC)
• Inventors: Collins, Ian Ralph, Bates, Christopher Ian, Ravenscroft, Paul Derek
• Granted Patent: US 6,764,980 B2
• Time in Patent Office: Days
• US Class Current: 507/90
• CPC Class Codes: C09K 8/536 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: C09K 8/54 Compositions for in situ inhibition of corrosion in boreholes or wells
• CPC Class Codes: C09K 8/92 characterised by their form or by the form of their components, e.g. encapsulated material C09K8/70 takes precedence
• CPC Class Codes: Y10S 507/901 Organically modified inorganic solid
• CPC Class Codes: Y10S 507/902 Controlled release agent
• CPC Class Codes: Y10S 507/906 Solid inorganic additive in defined physical form
• CPC Class Codes: Y10S 507/939 Corrosion inhibitor

Abstract

An oil field production chemical, especially a scale inhibitor, is in the form of particles thereof carrying a coating e.g. of a dispersing agent. The coating may be polymeric such as an oligomeric polyacid polyester, a polymeric alkoxylated alcohol or a fatty acid polyamine condensate or it may also be a surfactant and may be used in the form of a suspension in an inert oil, such as diesel oil or kerosene which may be injected into a subterranean formation to inhibit the formation of deposits, e.g. scale in oil wells over a longer period than compounds free of the coating.

Claims

1. Particles of a solid comprising an oil field production chemical, said solid carrying a coating, which comprises a dispersing agent, the weight of said coating being 0.1-10 g coating per 100 g of the particles.

2. Particles according to claim 1 wherein the coating also comprises a polymer.

3. Particles according to claim 1 wherein the dispersing agent is polymeric.

4. Particles according to claim 3, wherein the oil field production chemical is a polar organic compound.

5. Particles according to claim 4 wherein the oil field production chemical and the polymeric dispersing agent do not have the same charge.

6. Particles according to claim 3, wherein the dispersing agent is neutral, basic or cationic.

7. Particles according to claim 6 wherein the oil field production chemical is a polymeric anionic compound and the dispersing agent is non ionic, basic or cationic.

8. Particles according to claim 3 wherein the polymeric dispersing agent is of the comb type.

9. Particles according to claim 3 wherein the polymeric dispersing agent has an organic backbone with pendant hydrophilic and hydrophobic groups.

10. Particles according to claim 3 wherein the polymeric dispersing agent has a polar organic backbone with pendant hydrophobic groups.

11. Particles as claimed in claim 3 wherein the polymer is an oligomeric polyacid polyester or amine derivative thereof.

12. Particles as claimed in claim 1 wherein the coating comprises a surfactant.

13. Particles as claimed in claim 12 wherein the surfactant is a polymeric or monomeric alkoxylated alcohol or phenol.

14. Particles as claimed in claim 12 wherein the surfactant is a polymeric ether.

15. Particles as claimed in claim 9 wherein the polymer has a hydrocarbon backbone with at least one pendant oxygen and/or nitrogen containing polar group.

16. Particles as claimed in claim 15 wherein the polymer is an aliphatic (N-heterocyclic)carbonyl polymer.

17. Particles as claimed in claim 16 wherein the aliphatic (N-heterocyclic)carbonyl polymer is an alkylated derivative of polyvinylpyrrolidone.

18. Particles as claimed in claim 15 wherein the dispersing agent is an acetal of polyvinyl alcohol with an aldehyde.

19. Particles as claimed in claim 18 wherein the dispersing agent is a polyvinyl butyral vinyl alcohol polymer.

20. Particles as claimed in claim 10 wherein the dispersing agent comprises a fatty acid polyamine condensate.

21. Particles as claimed in claim 1 wherein the oil field production chemical is a scale inhibitor, a corrosion inhibitor, an asphaltene inhibitor, a wax inhibitor or a demulsifier.

22. Particles as claimed in claim 21 wherein the scale inhibitor is a polymeric compound.

23. Particles as claimed in claim 22 wherein the polymeric compound is a polyvinyl sulphonic acid, a poly(meth)acrylic acid or a copolymer of a vinylsulphonic acid and a (meth)acrylic acid or an alkali metal salt thereof.

24. Particles as claimed in claim 23 wherein the dispersing agent is basic or cationic.

25. Particles according to claim 23 wherein the dispersing agent is a polymer with a hydrocarbon backbone and at least one pendant hydrophobic group and at least one pendant nitrogen containing polar hydrophilic group.

26. Particles according to claim 25 wherein the dispersing agent is an aliphatic (N-heterocyclic)carbonyl polymer.

27. Particles according to claim 26 wherein the aliphatic (N-heterocyclic)carbonyl polymer is an alkylated derivative of polyvinylpyrrolidone.

28. Particles according to claim 24 wherein the dispersing agent has a polar organic backbone with pendant hydrophobic groups.

29. Particles according to claim 28 wherein the dispersing agent comprises a fatty acid polyamine condensate.

30. Particles according to claim 23 wherein the dispersing agent is a polyvinyl butyral vinyl alcohol polymer.

32. Particles as claimed in claim 1 wherein the relative weight of the coating to the particle is 0.5-5 g coating dry weight per 100 g of dry weight particle.

33. Particles as claimed in claim 1 wherein the average size of the particles is 1-10 microns.

36. A suspension as claimed in claim 35 wherein the inert oil is diesel oil or kerosene.

37. A suspension as claimed in claim 35 or 36 which also comprises an organophilic thickening agent or viscosifier.

38. A suspension according to claim 35 which also comprises a dispersing agent dissolved in said oil.

40. A method according to claim 39 which comprises injecting particles of an inhibitor of solid growth formation.

41. A method according to claim 40 wherein particles of scale inhibitor are injected into the formation and the scale inhibitor is released into the formation water.

31. Particles comprising an oil field production chemical having a coating comprising a material selected from:

a) a comb type polymer,

b) polymeric or monomeric alkoxylated alcohol or phenol,

c) polymeric ether.

d) a polymer with a hydrocarbon backbone with at least one pendant oxygen and/or nitrogen containing polar group which is an aliphatic (N-heterocyclic) carbonyl polymer.

34. A process for the manufacture of particles of an oil field production chemical, wherein a solid particulate oil field production chemical is comminuted in the presence of a dispersion of a dispersing agent in an inert oil to cause the dispersing agent to adhere to at least part of the surface of the particle to form a coating on said particle, the weight of coating to said particles being 0.1-10%.

35. A suspension comprising an inert oil and particles of a solid comprising an oil field production chemical, said solid carrying a coating, which comprises a dispersing agent, the weight of said coating being 0.1-10 g coating per 100 g of the particles.

39. A method of reducing the formation of a separate phase from a liquid phase in a subterranean environment producing oil, or removing said separate phase, which comprises injecting into said environment particles of a solid comprising an oil field production chemical, said solid carrying a coating, which comprises a dispersing agent, the weight of said coating being 0.1-10 g coating per 100 g of the particles.