Orthoester compositions and methods of use in subterranean applications

• US 20050034868A1
• Filed: 01/07/2004
• Published: 02/17/2005
• Est. Priority Date: 08/14/2003
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Citrowske, Bessie Nita Q., Funkhouser, Gary P., Frost, Keith A., Todd, Brad L.
• Granted Patent: US 7,140,438 B2
• Time in Patent Office: Days
• US Class Current: 166/307
• CPC Class Codes: C09K 8/52 Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
• CPC Class Codes: C09K 8/805 Coated proppants
• CPC Class Codes: Y10S 507/906 Solid inorganic additive in defined physical form
• CPC Class Codes: Y10S 507/924 with specified propping feature
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/2996 Glass particles or spheres

Abstract

The present invention relates to methods and compositions for treating subterranean formations, and more specifically, to improved methods and compositions for generating acids for use downhole, for example, to at least partially degrade the acid-soluble portions of filter cakes deposited in subterranean formations. In one embodiment, the present invention provides a method of degrading an acid-soluble portion of a filter cake comprising contacting the acid-soluble portion of the filter cake with an acid generated from an orthoester.

Claims

1. A method of degrading an acid-soluble portion of a filter cake comprising contacting the acid-soluble portion of the filter cake with an acid generated from an orthoester.

2. The method of claim 1 wherein the orthoester has the general formula RC(OR′

)(OR″

)(OR′

″

), wherein R′

, R″

, and R′

″

are not hydrogen, and R′

, R″

, and R′

″

may or may not be the same group.

3. The method of claim 2 wherein R′

, R″

, or R′

″

comprise a heteroatom.

4. The method of claim 3 wherein the heteroatom is nitrogen or oxygen.

5. The method of claim 1 wherein the orthoester comprises an orthoacetate, an orthoformate, or an orthopropionate.

6. The method of claim 1 wherein the orthoester comprises an orthoester of a polyfunctional alcohol.

7. The method of claim 1 wherein the orthoester comprises a poly(orthoester).

8. The method of claim 1 wherein the filter cake further comprises a polymeric portion, and wherein a component that is capable of degrading the polymeric portion of the filter cake is used to at least partially degrade the polymeric portion of the filter cake.

9. The method of claim 8 wherein the component capable of degrading the polymeric portion of the filter cake comprises an enzyme or an oxidizer.

10. The method of claim 1 wherein at least a portion of the orthoester is coated or impregnated onto particulates to form coated particulates or impregnated particulates.

11. The method of claim 10 wherein the particulates comprise natural sand, quartz sand, particulate garnet, glass, ground walnut hull, polymeric pellet, bauxite, or a ceramic.

12. The method of claim 10 wherein the particulates are in a size range from about 4 to about 100 US mesh.

13. The method of claim 10 wherein the particulates are in a size range from about 10 to about 70 US mesh.

14. The method of claim 10 wherein the orthoester is coated onto the particulates using an on-the-fly method.

15. The method of claim 10 wherein the orthoester is coated onto the particulates in a batch process.

16. The method of claim 10 wherein the coated particulates or impregnated particulates comprise a portion of a fracturing or gravel pack fluid.

17. A method of generating an acid in a subterranean formation comprising the steps of:

providing an orthoester composition that comprises an orthoester;

placing the orthoester composition in the formation; and

allowing the orthoester to generate an acid in the formation.

18. The method of claim 17 wherein the orthoester has the general formula RC(OR′

)(OR″

)(OR′

″

), wherein R′

, R″

, and R′

″

are not hydrogen, and R′

, R″

, and R′

″

may or may not be the same group.

19. The method of claim 18 wherein R′

, R″

, or R′

″

comprise a heteroatom.

20. The method of claim 19 wherein the heteroatom is nitrogen, or oxygen.

21. The method of claim 17 wherein the orthoester comprises an orthoacetate, an orthoformate, or an orthopropionate.

22. The method of claim 17 wherein the orthoester comprises an orthoester of a polyfunctional alcohol.

23. The method of claim 17 wherein the orthoester comprises from about 1% to about 100% of the orthoester composition.

24. The method of claim 17 wherein the orthoester composition comprises an inhibitor.

25. The method of claim 24 wherein the inhibitor comprises sodium hydroxide, potassium hydroxide, an amine, sodium carbonate, or a combination thereof.

26. The method of claim 17 wherein at least a portion of the orthoester composition is coated or impregnated onto particulates to form coated particulates or impregnated particulates.

27. The method of claim 26 wherein the coated particulates or impregnated particulates comprise a portion of a fracturing or gravel pack fluid.

28. The method of claim 26 wherein less than 100% of the particulates are coated or impregnated with the orthoester composition.

29. The method of claim 17 wherein the orthoester composition is in a solution form, gel form, or an emulsion form.

30. The method of claim 29 wherein the solution form comprises propylene glycol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monobutyl ether, or water.

31. The method of claim 29 wherein the gel form comprises a polymer or a surfactant.

32. The method of claim 29 wherein the emulsion form comprises an emulsifier.

33. A method of degrading an acid soluble component in a subterranean formation comprising the steps of:

providing an orthoester composition that comprises an orthoester;

placing the orthoester composition in the formation;

allowing the orthoester to generate a generated acid; and

allowing the generated acid to at least partially degrade the acid soluble component.

34. The method of claim 33 wherein the acid soluble component is a portion of a filter cake.

35. The method of claim 33 wherein the orthoester has the general formula RC(OR′

)(OR″

)(OR′

″

), wherein R′

, R″

, and R′

″

are not hydrogen, and R′

, R″

, and R′

″

may or may not be the same group.

36. The method of claim 35 wherein R′

, R″

, or R′

″

comprise a heteroatom.

37. The method of claim 36 wherein the heteroatom is nitrogen or oxygen.

38. The method of claim 33 wherein the orthoester comprises an orthoester of a polyfunctional alcohol.

39. The method of claim 33 wherein the orthoester composition comprises an inhibitor capable of interacting with the acid so as to delay the degradation of the acid soluble component by the acid.

40. The method of claim 39 wherein the inhibitor comprises sodium hydroxide, potassium hydroxide, an amine, sodium carbonate, or a combination thereof.

41. The method of claim 33 wherein at least a portion of the orthoester composition is coated or impregnated onto particulates to form coated particulates or impregnated particulates.

42. The method of claim 33 wherein the orthoester composition is in a solution form, gel form, or an emulsion form.

43. The method of claim 33 wherein the acid soluble component comprises a portion of the subterranean formation, calcium carbonate, a thermosetting resin, or a portion of a piece of completion equipment.

44. A method of degrading a filter cake in a subterranean formation comprising the steps of:

providing particulates coated or impregnated with an orthoester composition that comprises an orthoester;

placing the particulates into the subterranean formation so that they are substantially adjacent to the filter cake;

allowing the orthoester to generate a generated acid; and

allowing the generated acid to degrade at least a portion of an acid-soluble portion of the filter cake.

45. The method of claim 44 wherein the orthoester has the general formula RC(OR′

)(OR″

)(OR′

″

), wherein R′

, R″

, and R′

″

are not hydrogen, and R′

, R″

, and R′

″

may or may not be the same group.

46. The method of claim 45 wherein R′

, R″

, or R′

″

comprise a heteroatom.

47. The method of claim 44 wherein the orthoester comprises an orthoester of a polyfunctional alcohol.

48. The method of claim 44 wherein the orthoester composition comprises an inhibitor that is capable of delaying the degradation of the acid soluble portion of the filter cake by the generated acid.

49. The method of claim 48 wherein the inhibitor comprises sodium hydroxide, potassium hydroxide, an amine, sodium carbonate, or a combination thereof.

50. The method of claim 44 wherein the particulates comprise natural sand, quartz sand, particulate garnet, glass, ground walnut hull, polymeric pellet, bauxite, or a ceramic.

51. A composition capable of degrading an acid soluble component in a subterranean formation comprising an orthoester that will generate an acid that is capable of degrading at least a portion of the acid soluble component.

52. The composition of claim 51 wherein the orthoester has the general formula RC(OR′

)(OR″

)(OR′

″

), wherein R′

, R″

, and R′

″

are not hydrogen, and R′

, R″

, and R′

″

may or may not be the same group.

53. The composition of claim 52 wherein R′

, R″

, or R′

″

comprise a heteroatom.

54. The composition of claim 53 wherein the heteroatom is hydrogen, nitrogen, or oxygen.

55. The composition of claim 51 wherein the orthoester comprises an orthoacetate, an orthoformate, or an orthopropionate.

56. The composition of claim 51 wherein the orthoester comprises an orthoester of a polyfunctional alcohol.

57. The composition of claim 51 further comprising an inhibitor.

58. The composition of claim 57 wherein the inhibitor comprises sodium hydroxide, potassium hydroxide, an amine, sodium carbonate, or a combination thereof.