Claims
- 1. An expandable downhole tool for use with a drilling assembly in a wellbore, comprising:
a tubular body; at least one moveable arm disposed within said tubular body and being radially translatable between a retracted position and a wellbore engaging position; and at least one piston operable to mechanically support said at least one moveable arm in said wellbore engaging position when an opposing force is exerted.
- 2. The tool of claim 1 wherein said at least one piston is axially translatable in response to a differential pressure between an axial flowbore within said tool and said wellbore.
- 3. The tool of claim 1 wherein said tubular body further includes at least one pocket for storing said at least one moveable arm in said retracted position.
- 4. The tool of claim 1 wherein said at least one moveable arm comprises a plurality of moveable arms.
- 5. The tool of claim 1 wherein said at least one moveable arm includes at least one set of cutting structures for reaming said wellbore in said wellbore engaging position.
- 6. The tool of claim 1 further comprising at least one gage pad for stabilizing said drilling assembly in said wellbore engaging position.
- 7. The tool of claim 6 wherein said at least one gage pad is removable and replaceable.
- 8. The tool of claim 6 further comprising cutters adjacent said at least one gage pad.
- 9. The tool of claim 2 further comprising a sliding sleeve biased to isolate said at least one piston from said axial flowbore, thereby preventing said at least one moveable arm from translating between said retracted position and said well-bore engaging position.
- 10. The tool of claim 9 further comprising a droppable or pumpable actuator for aligning said sliding sleeve to expose said at least one piston to said axial flowbore.
- 11. The tool of claim 1 wherein said at least one moveable arm comprises a back-reaming cutter.
- 12. The tool of claim 1 further comprising at least one nozzle disposed adjacent said at least one moveable arm.
- 13. The tool of claim 1 wherein said tool comprises a concentric expandable reamer.
- 14. A method of reaming a formation to form an enlarged borehole in a wellbore, comprising:
disposing an expandable reamer in a retracted position in the wellbore; expanding at least one movable arm of the expandable reamer radially outwardly into engagement with the formation; reaming the formation with the at least one moveable arm to form the enlarged borehole; and mechanically supporting the at least one moveable arm in the radially outward direction during reaming.
- 15. The method of claim 14 further comprising back-reaming the formation with the at least one moveable arm.
- 16. The method of claim 14 further comprising:
flowing a fluid through the expandable reamer; and selectively driving the at least one movable arm radially outwardly in response to the flowing fluid.
- 17. The method of claim 16 further comprising mechanically retracting the at least one moveable arm radially inwardly.
- 18. The method of claim 16 further comprising flowing a portion of the fluid across a wellbore engaging portion of the at least one moveable arm.
- 19. The method of claim 14 further comprising providing a pressure indication during or after the at least one moveable arm is expanded radially outwardly.
- 20. The method of claim 14 further comprising providing stability and gage protection as the reaming progresses.
- 21. The method of claim 14 further comprising removing a formation engaging portion of the expandable reamer without removing the at least one moveable arm.
- 22. The method of claim 14 further comprising replacing a formation engaging portion of the expandable reamer without removing the at least one moveable arm.
- 23. The method of claim 14 wherein the expanding step is performed without substantially axially moving the expandable reamer within the wellbore.
- 24. An expandable downhole tool for use in a drilling assembly positioned within a wellbore, comprising:
a tubular body including an axial flowbore extending therethrough; a piston disposed within said axial flowbore having at least one cam portion with a substantially flat surface; and at least one moveable arm engaging said piston; wherein said piston is axially translatable in response to a differential pressure between said axial flowbore and said wellbore, and wherein said at least one moveable arm is radially translatable between a retracted position and an expanded position.
- 25. The tool of claim 24 wherein said substantially flat surface on said cam portion engages a substantially flat surface on said at least one moveable arm in said expanded position.
- 26. The tool of claim 24 further including a biasing spring to bias said at least one moveable arm to said retracted position.
- 27. The tool of claim 26 wherein said biasing spring is disposed in a spring chamber filled with drilling fluid from the wellbore.
- 28. The tool of claim 26 wherein said biasing spring is disposed in an oil-filled spring chamber.
- 29. The tool of claim 28 further comprising a pressure compensation system.
- 30. The tool of claim 24 wherein said tubular body further includes at least one pocket for storing said at least one moveable arm in said retracted position.
- 31. The tool of claim 24 wherein said at least one moveable arm comprises three moveable arms spaced apart circumferentially around said tubular body.
- 32. The tool of claim 24 wherein said at least one moveable arm includes a plurality of cylindrical blades.
- 33. The tool of claim 32 wherein each of said blades comprises a fixed blade portion and a removeable blade portion.
- 34. The tool of claim 24 wherein said at least one moveable arm engages said wellbore in said expanded position.
- 35. The tool of claim 34 wherein said at least one moveable arm includes at least one set of cutting structures for reaming said wellbore in said expanded position.
- 36. The tool of claim 34 wherein said at least one moveable arm includes at least one gage pad for stabilizing said drilling assembly within said wellbore.
- 37. The tool of claim 36 further comprising cutters adjacent said at least one gage pad.
- 38. The tool of claim 24 further including ports in fluid communication with said flowbore and said piston.
- 39. The tool of claim 38 further including a sliding sleeve biased to close said ports, thereby preventing said at least one moveable arm from translating between said retracted position and said expanded position in response to said differential pressure.
- 40. The tool of claim 39 further including a bullet actuator for aligning said sliding sleeve to open said ports.
- 41. The tool of claim 26 wherein said biasing spring comprises at least one radial spring.
- 42. The tool of claim 31 wherein each of said three moveable arms comprises a gage surface area.
- 43. The tool of claim 42 wherein each of said gage surface areas comprises at least one cutting structure and at least one gage pad area.
- 44. The tool of claim 43 wherein a combination of said gage surface areas of said three moveable arms comprises a complete overlap of an aggressive cutting structure and a complete overlap of a smooth gage pad.
- 45. The tool of claim 24 wherein said at least one moveable arm comprises a back-reaming cutter.
- 46. The tool of claim 24 wherein said at least one moveable arm comprises a tapered surface to engage a casing and radially translate said arm from the expanded position to the retracted position.
- 47. A drilling assembly comprising said expandable downhole tool of claim 24.
- 48. The drilling assembly of claim 47 wherein said expandable downhole tool is positionable anywhere on the drilling assembly upstream of the drill bit.
- 49. The tool of claim 24 wherein said tool is shorter than about 14-feet long.
- 50. The tool of claim 24 wherein said tool is approximately 4-feet long.
- 51. The tool of claim 24 wherein said at least one moveable arm is radially translatable between said retracted position and said expanded position via a combination of hydraulic and mechanical activation.
- 52. The tool of claim 51 wherein said hydraulic activation comprises changing said differential pressure to axially translate said piston.
- 53. The tool of claim 51 wherein said mechanical activation comprises said at least one cam portion engaging at least one tapered portion on said at least one moveable arm while said piston axially translates, thereby forcing said at least one moveable arm to radially translate from said retracted position to said expanded position.
- 54. The tool of claim 51 wherein said mechanical activation comprises a radial spring that biases said at least one moveable arm radially inwardly from said expanded position to said retracted position.
- 55. The tool of claim 25 wherein said at least one cam portion further comprises a tapered piston surface.
- 56. The tool of claim 55 wherein said tapered piston surface engages a tapered blade surface on said at least one moveable arm as the at least one moveable arm is radially translated from the retracted position to the expanded position.
- 57. The tool of claim 55 wherein said piston comprises a plurality of said cam portions separated by at least one notch.
- 58. The tool of claim 57 wherein said at least one moveable arm comprises at least one blade portion that resides in said at least one notch in said retracted position.
- 59. The tool of claim 24 further comprising shear pins that prevent said at least one moveable arm from radially translating to the expanded position until said differential pressure is sufficient to break said shear pins.
- 60. The tool of claim 24 further comprising at least one nozzle disposed adjacent said at least one moveable arm.
- 61. The tool of claim 24 wherein said tool comprises a concentric expandable reamer.
- 62. The tool of claim 24 wherein said tool comprises a concentric expandable stabilizer.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C. § 119 of U.S. provisional application Serial No. 60/468,767 filed May 8, 2003 and entitled “Concentric Expandable Reamer”, hereby incorporated herein by reference for all purposes.
Provisional Applications (1)
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Number |
Date |
Country |
|
60468767 |
May 2003 |
US |