Lead the Bit Rotary Steerable Tool

• US 20100000794A1
• Filed: 09/11/2009
• Published: 01/07/2010
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Turner, Paula, Hall, David R., Woolston, Scott, Lundgreen, David
• Granted Patent: US 8,522,897 B2
• Time in Patent Office: Days
• US Class Current: 175/61
• CPC Class Codes: E21B 7/064 specially adapted drill bits therefor
• CPC Class Codes: E21B 7/067 with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub
• CPC Class Codes: E21B 7/068 drilled by a down-hole drilling motor down-hole drives per se E21B4/00, E21B7/067 takes precedence

Abstract

In one aspect of the present invention, a drilling assembly comprises a drill bit comprising a bit body intermediate a working face and a shank. An indenting member adapted to guide the drill bit protrudes from the working face. A flexible portion is disposed above the bit body.

Claims

1. A method for steering a downhole tool string, comprising:

providing a drill bit assembly attached to an end of the tool string disposed within a bore hole;

providing a shaft protruding from a working portion of the drill bit assembly; and

angularly pushing off the formation with the shaft.

2. The method of claim 1, wherein pushing off the formation comprises pushing the drill bit assembly along a desired trajectory by the shaft.

3. The method of claim 1, wherein pushing off the formation comprises angling the shaft.

4. The method of claim 1, wherein the shaft advances along the desired trajectory before the drill bit assembly.

5. The method of claim 1, wherein the shaft is disposed within a chamber generally coaxial with a shank portion of the drill bit assembly.

6. The method of claim 1, wherein the drill bit assembly comprises an actuator for angling the distal end of the shaft with respect to a shank portion of the assembly.

7. The method of claim 6 wherein the actuator is rotationally isolated from a working portion of the drill bit assembly.

8. The method of claim 6 wherein the actuator for angling the drill bit assembly is controlled over a downhole network or a downhole tool.

9. The method of claim 1, wherein the shaft is rotationally isolated from the bit.

10. The method of clam 1, wherein a body of the drill bit assembly is adapted to rotate around the shaft.

11. A method for steering a downhole tool string, comprising:

providing a drill bit assembly attached to an end of the tool string disposed within a bore hole; and

angularly pushing off the formation in front of the bit with a shaft connected to the drill bit assembly.

12. The method of claim 11, wherein pushing off the formation comprises pushing the drill bit assembly along a desired trajectory by the shaft.

13. The method of claim 11, wherein pushing off the formation comprises angling the shaft.

14. The method of claim 11, wherein the shaft advances along the desired trajectory before the drill bit assembly.

15. The method of claim 11, wherein the shaft is disposed within a chamber generally coaxial with a shank portion of the drill bit assembly.

16. The method of claim 11, wherein the drill bit assembly comprises an actuator for angling the distal end of the shaft with respect to a shank portion of the assembly.

17. The method of claim 16, wherein the actuator is rotationally isolated from a working portion of the drill bit assembly.

18. The method of claim 11, wherein the drill bit comprises a flexible portion.

19. The method of claim 11, wherein the shaft is rotationally isolated from the bit assembly.

20. The method of clam 11, wherein a body of the drill bit assembly is adapted to rotate around the shaft.