Methods and Compositions for Fracturing Subterranean Formations

• US 20080202744A1
• Filed: 02/26/2007
• Published: 08/28/2008
• Est. Priority Date: 02/26/2007
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Huang, Tianping, Crews, James B., Willingham, John R., Gabrysch, Allen D., Wood, William R., Treadway, James H., KELLY, Patrick A.
• Granted Patent: US 7,723,272 B2
• Time in Patent Office: Days
• US Class Current: 166/246
• CPC Class Codes: C09K 2208/24 Bacteria or enzyme containing gel breakers
• CPC Class Codes: C09K 2208/26 Gel breakers other than bacteria or enzymes
• CPC Class Codes: C09K 2208/30 Viscoelastic surfactants [VES]
• CPC Class Codes: C09K 8/602 containing surfactants
• CPC Class Codes: C09K 8/68 containing organic compounds

Abstract

Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

Claims

1. A method for treating a subterranean formation comprising:

providing a viscoelastic surfactant gelled treating fluid composition comprising;

water;

at least one viscoelastic surfactant (VES) in an amount effective to increase the viscosity of the water;

at least one internal breaker; and

at least one fluid loss control agent;

introducing the treating fluid composition into the subterranean formation;

treating the subterranean formation; and

reducing the viscosity of the treating fluid composition.

2. The method of claim 1 where the internal breaker is selected from the group consisting of bacteria, transition metal ion sources, saponified fatty acids, mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids, and combinations thereof.

3. The method of claim 2 where the saponified fatty acids are soap reaction products of a fatty acid with an alkaline compound selected from the group consisting of organic bases, alkali metal bases, alkali earth metal bases, ammonium bases, and combinations thereof.

4. The method of claim 2 where the unsaturated fatty acids are selected from the group consisting of monoenoic acids, polyenoic acids, and mixtures thereof.

5. The method of claim 2 where:

when the internal breaker is bacteria, the amount of bacteria ranges from about 0.01 to about 20.0 vol %;

when the internal breaker is a transition metal ion source, the amount of transition metal ion from the transition metal ion source ranges from about 0.01 to about 300 ppm;

when the internal breaker is a saponified fatty acid, the amount of saponified fatty acid ranges from about 50 to about 20,000 ppm; and

when the internal breaker is selected from the group consisting of mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids and combinations thereof, the amount of internal breaker ranges from about 0.1 to about 20 gptg;

all based on the VES gelled fluid.

6. The method of claim 1 further comprising heating the VES gelled treating fluid composition to a temperature effective to cause the internal breaker to reduce the viscosity of the VES gelled fluid.

7. The method of claim 6 where the effective temperature ranges from about 100 to about 400°

F. (about 38 to about 204°

C.).

8. The method of claim 1 where the internal breaker is a mineral oil and is at least about 99 wt % paraffin.

9. The method of claim 1 where the VES gelled treating fluid composition further comprises at least one VES stabilizer.

10. The method of claim 9 where the VES stabilizer is selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, glycols, polyols, and combinations thereof.

11. The method of claim 1 where the at least one fluid loss control agent is selected from the group consisting of alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof.

12. The method of claim 11 where an amount of the fluid loss control agent ranges from about 2 to about 200 pptg (about 0.2 to about 24 kg/m³) based on the VES gelled fluid.

13. The method of claim 1 where the VES gelled treating fluid composition further comprises at least one viscosity enhancer.

14. The method of claim 13 where the at least one viscosity enhancer is selected from the group consisting of pyroelectric particles, piezoelectric particles, and mixtures thereof.

15. The method of claim 13 where in the VES gelled treating fluid composition:

the at least one VES is present in an amount of from about 0.5 to 12.0 vol %; and

the viscosity enhancer is present in an amount of from about 0.1 to about 500 pptg (about 0.012 to about 60 kg/m³);

all based on the VES gelled fluid.

16. The method of claim 1 where only one component is present in the VES gelled fluid that reduces viscosity, which is the at least one internal breaker.

17. The method of claim 1 where treating the subterranean formation is selected from the group consisting of:

fracturing the formation under an effective pressure where the aqueous viscoelastic treating fluid further comprises a proppant;

packing the formation with gravel where the aqueous viscoelastic treating fluid further comprises gravel;

stimulating the formation where the aqueous viscoelastic treating fluid further comprises a stimulating agent;

completing a well; and

controlling fluid loss where the aqueous viscoelastic treating fluid further comprises a salt, an easily removed solid, and a mixture thereof.

18. A method for fracturing a subterranean formation comprising:

introducing a viscoelastic surfactant gelled fluid into a subterranean formation, where the viscoelastic surfactant gelled fracturing fluid composition comprises;

water;

at least one viscoelastic surfactant (VES) in an amount effective to increase the viscosity of the water;

at least one internal breaker selected from the group consisting of bacteria, transition metal ion sources, saponified fatty acids, mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids, and combinations thereof;

at least one fluid loss control agent selected from the group consisting of alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof; and

at least one viscosity enhancer selected from the group consisting of pyroelectric particles, piezoelectric particles, and mixtures thereof;

pumping the fracturing fluid composition against the subterranean formation at sufficient rate and pressure to fracture the formation; and

reducing the viscosity of the VES gelled fluid with the internal breaker.

19. The method of claim 18 where the saponified fatty acids are soap reaction products of a fatty acid with an alkaline compound selected from the group consisting of organic bases, alkali metal bases, alkali earth metal bases, ammonium bases, and combinations thereof.

20. The method of claim 18 where the unsaturated fatty acids are selected from the group consisting of monoenoic acids, polyenoic acids, and mixtures thereof.

21. The method of claim 18 where:

when the internal breaker is bacteria, the amount of bacteria ranges from about 0.01 to about 20.0 vol %;

when the internal breaker is a transition metal ion source, the amount of transition metal ion from the transition metal ion source ranges from about 0.01 to about 300 ppm;

when the internal breaker is a saponified fatty acid, the amount of saponified fatty acid ranges from about 50 to about 20,000 ppm; and

when the internal breaker is selected from the group consisting of mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids and combinations thereof, the amount of internal breaker ranges from about 0.1 to about 20 gptg;

all based on the VES gelled fluid.

22. The method of claim 18 further comprising heating the VES gelled fluid to a temperature effective to cause the internal breaker to reduce the viscosity of the VES gelled fluid.

23. The method of claim 22 where the effective temperature ranges from about 100 to about 400°

F. (about 38 to about 204°

C.).

24. The method of claim 18 where the internal breaker is a mineral oil and is at least about 99 wt % paraffin.

25. The method of claim 18 where an amount of the fluid loss control agent ranges from about 2 to about 200 pptg (about 0.2 to about 24 kg/m³) based on the VES gelled fluid.

26. The method of claim 18 where in the VES gelled fluid:

the at least one VES is present in an amount of from about 0.5 to 12.0 vol %; and

the viscosity enhancer is present in an amount of from about 0.1 to about 500 pptg (about 0.012 to about 60 kg/m³);

all based on the VES gelled fluid.

27. The method of claim 18 where only one component is present in the VES gelled fluid that reduces viscosity, which is the at least one internal breaker.

28. The method of claim 18 where the internal breaker is present in an oil-soluble internal phase of the water of the VES gelled fluid.

29. The method of claim 18 where the VES gelled fracturing fluid composition further comprises at least one VES stabilizer selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, glycols, polyols, and combinations thereof;

30. A viscoelastic surfactant (VES) gelled subterranean formation treatment fluid comprising:

water;

at least one VES in an amount effective to increase the viscosity of the water;

at least one internal breaker; and

at least one fluid loss control agent.

31. The VES gelled subterranean formation treatment fluid of claim 30 where the internal breaker is selected from the group consisting of bacteria, transition metal ion sources, saponified fatty acids, mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids, and combinations thereof.

32. The VES gelled subterranean formation treatment fluid of claim 31 where the saponified fatty acids are soap reaction products of a fatty acid with an alkaline compound selected from the group consisting of organic bases, alkali metal bases, alkali earth metal bases, ammonium bases, and combinations thereof.

33. The VES gelled subterranean formation treatment fluid of claim 31 where the unsaturated fatty acids are selected from the group consisting of monoenoic acids, polyenoic acids, and mixtures thereof.

34. The VES gelled subterranean formation treatment fluid of claim 31 where:

when the internal breaker is bacteria, the amount of bacteria ranges from about 0.01 to about 20.0 vol %;

when the internal breaker is a transition metal ion source, the amount of transition metal ion from the transition metal ion source ranges from about 0.01 to about 300 ppm;

when the internal breaker is a saponified fatty acid, the amount of saponified fatty acid ranges from about 50 to about 20,000 ppm; and

when the internal breaker is selected from the group consisting of mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids and combinations thereof, the amount of internal breaker ranges from about 0.1 to about 20 gptg;

all based on the VES gelled fluid.

35. The VES gelled subterranean formation treatment fluid of claim 31 where the internal breaker is a mineral oil and is at least about 99 wt % paraffin.

36. The VES gelled subterranean formation treatment fluid of claim 30 further comprising at least one VES stabilizer.

37. The VES gelled subterranean formation treatment fluid of claim 36 where the VES stabilizer is selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, glycols, polyols, and combinations thereof.

38. The VES gelled subterranean formation treatment fluid of claim 30 where the at least one fluid loss control agent is selected from the group consisting of alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof.

39. The VES gelled subterranean formation treatment fluid of claim 30 where the amount of the fluid loss control agent ranges from about 2 to about 200 pptg (about 0.2 to about 24 kg/m³) based on the VES gelled fluid.

40. The VES gelled subterranean formation treatment fluid of claim 30 further comprising at least one viscosity enhancer.

41. The VES gelled subterranean formation treatment fluid of claim 40 where the at least one viscosity enhancer is selected from the group consisting of pyroelectric particles, piezoelectric particles, and mixtures thereof.

42. The VES gelled subterranean formation treatment fluid of claim 40 where in the VES gelled fluid:

the at least one VES is present in an amount of from about 0.5 to 12.0 vol %; and

the viscosity enhancer is present in an amount of from about 0.1 to about 500 pptg (about 0.012 to about 60 kg/m³);

all based on the VES gelled fluid.

43. The viscoelastic surfactant gelled subterranean formation treatment fluid of claim 30 where only one component is present in the treatment fluid that reduces viscosity, which is the at least one internal breaker.

44. The VES gelled subterranean formation treatment fluid of claim 30 where the internal breaker is present in an oil-soluble internal phase of the water of the VES gelled fluid.

45. A viscoelastic surfactant (VES) gelled subterranean formation treatment fluid comprising:

water;

at least one VES in an amount effective to increase the viscosity of the water;

at least one internal breaker selected from the group consisting of bacteria, transition metal ion sources, saponified fatty acids, mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids and combinations thereof; and

at least one fluid loss control agent selected from the group consisting of alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof; and

viscosity enhancer selected from the group consisting of pyroelectric particles, piezoelectric particles, and mixtures thereof.

46. The VES subterranean formation treatment fluid of claim 45 where the saponified fatty acids are soap reaction products of a fatty acid with an alkaline compound selected from the group consisting of organic bases, alkali metal bases, alkali earth metal bases, ammonium bases, and combinations thereof.

47. The VES gelled subterranean formation treatment fluid of claim 45 where the unsaturated fatty acids are selected from the group consisting of monoenoic acids, polyenoic acids, and mixtures thereof.

48. The VES gelled subterranean formation treatment fluid of claim 45 where:

when the internal breaker is bacteria, the amount of bacteria ranges from about 0.01 to about 20.0 vol %;

when the internal breaker is a transition metal ion source, the amount of transition metal ion from the transition metal ion source ranges from about 0.01 to about 300 ppm;

when the internal breaker is a saponified fatty acid, the amount of saponified fatty acid ranges from about 50 to about 20,000 ppm; and

when the internal breaker is selected from the group consisting of mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids and combinations thereof, the amount of internal breaker ranges from about 0.1 to about 20 gptg;

all based on the VES gelled fluid.

49. The VES gelled subterranean formation treatment fluid of claim 45 where the internal breaker is a mineral oil and is at least about 99 wt % paraffin.

50. The VES gelled subterranean formation treatment fluid of claim 45 where the amount of the fluid loss control agent ranges from about 2 to about 200 pptg (about 0.2 to about 24 kg/m³) based on the VES gelled fluid.

51. The VES gelled subterranean formation treatment fluid of claim 45 further comprising at least one VES stabilizer selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkali earth metal oxides, alkali earth metal hydroxides, transition metal oxides, transition metal hydroxides, glycols, polyols, and combinations thereof.

52. The VES gelled subterranean formation treatment fluid of claim 45 where in the VES gelled fluid:

the at least one VES is present in an amount of from about 0.5 to 12.0 vol %; and

the viscosity enhancer is present in an amount of from about 0.1 to about 500 pptg (about 0.012 to about 60 kg/m³);

all based on the VES gelled fluid.

53. The VES gelled subterranean formation treatment fluid of claim 45 where only one component is present in the treatment fluid that reduces viscosity, which is the at least one internal breaker.

54. The VES gelled subterranean formation treatment fluid of claim 45 where the internal breaker is present in an oil-soluble internal phase of the water of the VES gelled fluid.