METHODS OF INCREASING FRACTURE RESISTANCE IN LOW PERMEABILITY FORMATIONS

• US 20100282470A1
• Filed: 08/01/2008
• Published: 11/11/2010
• Est. Priority Date: 08/01/2007
• Status: Active Grant

• Current Assignee: Alcon Incorporated, BP Corporation North America Incorporated (BP PLC), M-I LLC (SLB)
• Original Assignee: BP Corporation North America Incorporated (BP PLC), M-I LLC (SLB)
• Inventors: Sant, Randall, Aston, Mark, Sanders, Mark, Friedheim, Jim, Alberty, Mark William
• Granted Patent: US 9,103,206 B2
• Time in Patent Office: Days
• US Class Current: 166/308.1
• CPC Class Codes: E21B 33/138 Plastering the borehole wall; Injecting into the formation
• CPC Class Codes: E21B 43/26 by forming crevices or fractures

Abstract

A method of increasing the fracture resistance of a low permeability formation that includes emplacing a wellbore fluid in a wellbore through the low permeability formation, the wellbore fluid comprising: a settable carrier fluid; and a solid particulate bridging material; increasing the pressure in the wellbore such that fractures are formed in the formation; allowing the settable carrier fluid to enter the fractures; bridging and sealing the mouths of the fractures to form a substantially impermeable bridge proximate the mouth of the fractures thereby strengthening the formation; and holding the increased pressure for an amount of time sufficient for setting of the carrier fluid in the fractures is disclosed.

Claims

1. A method of increasing the fracture resistance of a low permeability formation, comprising:

emplacing a wellbore fluid in a wellbore through the low permeability formation, the wellbore fluid comprising;

a settable carrier fluid; and

a solid particulate bridging material;

increasing the pressure in the wellbore such that fractures are formed in the formation;

allowing the settable carrier fluid to enter the fractures;

bridging and sealing the mouths of the fractures to form a substantially impermeable bridge proximate the mouth of the fractures thereby strengthening the formation; and

holding the increased pressure for an amount of time sufficient for setting of the carrier fluid in the fractures.

2. The method of claim 1, wherein the pressure is increased to above an initial fracture pressure of the formation to induce fractures in the wellbore.

3. The method of claim 1, wherein the pressure is increased to above a re-opening pressure of the formation to re-open fractures in the wellbore.

4. The method of claim 1, wherein the bridging and sealing prevents fracture propagation.

5. The method of claim 1, wherein the solid particulate bridging material bridges and seals the mouth of the fracture.

6. The method of claim 1, wherein the wellbore fluid further comprises a bridge sealing material to seal the bridge proximate the mouth of the fracture.

7. The method of claim 1, wherein the solid particulate bridging material comprises at least one of calcium carbonate, graphite, dolomite, celluloses, micas, sand, and ceramic particles.

8. The method of claim 1, wherein the set carrier fluid possesses a compressive strength sufficient to prevent extrusion of the set fluid out of the fracture.

9. The method of claim 1, wherein the set carrier fluid comprises a compressive strength less than that of the formation.

10. The method of claim 1, wherein the set carrier fluid comprises a compressive strength ranging from one-third of to less than a compressive strength of the formation.

11. The method of claim 1, wherein the low permeability formation comprises shale.

12. The method of claim 7, wherein the settable carrier fluid chemically adheres to the shale.

13. The method of claim 1, wherein the settable carrier fluid comprises cementious material.

14. The method of claim 1, wherein the settable carrier fluid comprises at least one monomer and a hardening agent.

15. The method of claim 14, wherein the settable carrier fluid comprises at least one epoxide and at least one polyamine.

16. The method of claim 14, wherein the settable carrier fluid comprises at least one epoxidized natural oil and at least one polyetheramine.

17. A method of drilling a wellbore through a low permeability formation, comprising:

drilling the wellbore while circulating a first wellbore fluid into the wellbore;

emplacing a wellbore fluid in a wellbore through the low permeability formation, the wellbore fluid comprising;

a settable carrier fluid; and

a solid particulate bridging material;

increasing the pressure in the wellbore such that fractures are formed in the formation;

allowing the settable carrier fluid to enter the fractures;

bridging and sealing the mouths of the fractures to form a substantially impermeable bridge proximate the mouth of the fractures thereby strengthening the formation; and

holding the increased pressure for an amount of time sufficient for setting of the carrier fluid in the fractures.

18. The method of claim 17, wherein the pressure is increased to above an initial fracture pressure of the formation to induce fractures in the wellbore.

19. The method of claim 17, wherein the pressure is increased to above a re-opening pressure of the formation to re-open fractures in the wellbore.

20. The method of claim 17, wherein the bridging and sealing prevents fracture propagation.

21. The method of claim 17, wherein the solid particulate bridging material bridges and seals the mouth of the fracture.

22. The method of claim 17, wherein the wellbore fluid further comprises a bridge sealing material to seal the bridge proximate the mouth of the fracture.

23. The method of claim 17, wherein the solid particulate bridging material comprises at least one of calcium carbonate, graphite, dolomite, celluloses, micas, sand, and ceramic particles.

24. The method of claim 17, wherein the set carrier fluid possesses a compressive strength sufficient to prevent extrusion of the set fluid out of the fracture.

25. The method of claim 17, wherein the set carrier fluid comprises a compressive strength less than that of the formation.

26. The method of claim 17, wherein the set carrier fluid comprises a compressive strength ranging from one-third of to less than a compressive strength of the formation.

27. The method of claim 17, wherein the low permeability formation comprises shale.

28. The method of claim 27, wherein the settable carrier fluid chemically adheres to the shale.

29. The method of claim 17, wherein the settable carrier fluid comprises cementious material.

30. The method of claim 17, wherein the settable carrier fluid comprises at least one monomer and a hardening agent.

31. The method of claim 30, wherein the settable carrier fluid comprises at least one epoxide and at least one polyamine.

32. The method of claim 30, wherein the settable carrier fluid comprises at least one epoxidized natural oil and at least one polyetheramine.

33. A method of increasing the fracture resistance of a low permeability formation, comprising:

emplacing a wellbore fluid in a wellbore through the low permeability formation, the wellbore fluid comprising;

a settable carrier fluid comprising;

an oleaginous base fluid;

an epoxidized natural oil; and

at least one crosslinking agent;

a solid particulate bridging material; and

a bridge sealing material;

increasing the pressure in the wellbore to above an initial or re-opening fracture pressure of the formation such that fractures are induced in the formation;

allowing the settable carrier fluid to enter the fractures, the solid particulate bridging material to prop open the fractures, and the bridge sealing material to form a substantially fluid impermeable bridge proximate the mouths of the fractures, thereby strengthening the formation and preventing the fractures from further growth in length; and

holding the increased pressure for an amount of time sufficient for setting of the carrier fluid in the fractures.

34. A method of increasing the fracture resistance of a low permeability formation, comprising:

emplacing a wellbore fluid in a wellbore through the low permeability formation, the wellbore fluid comprising;

a settable carrier fluid comprising;

water; and

a cementious material;

a solid particulate bridging material; and

a bridge sealing material;

increasing the pressure in the wellbore to above an initial or re-opening fracture pressure of the formation such that fractures are induced in the formation;

allowing the settable carrier fluid to enter the fractures, the solid particulate bridging material to prop open the fractures, and the bridge sealing material to form a substantially fluid impermeable bridge proximate the mouths of the fractures, thereby strengthening the formation and preventing the fractures from further growth in length; and

holding the increased pressure for an amount of time sufficient for setting of the carrier fluid in the fractures.