Downhole assembly

• US 8,622,153 B2
• Filed: 09/04/2008
• Issued: 01/07/2014
• Est. Priority Date: 09/04/2007
• Status: Expired due to Fees

• Current Assignee: George Swietlik, Stephen John Mcloughlin
• Original Assignee: George Swietlik, Stephen John Mcloughlin
• Inventors: McLoughlin, Stephen John, Swietlik, George
• Primary Examiner(s): HUTCHINS, CATHLEEN R
• Application Number:
  US12/733,480
• Publication Number:
  US 20110120772A1
• Time in Patent Office: 1,951 Days
• Field of Search: 166/241.6, 166/241.1, 175/325.1, 175/325.3, 175/325.5, 175/325.4, 175/56
• US Class Current: 175/325.5
• CPC Class Codes: E21B 17/05 Swivel joints
• CPC Class Codes: E21B 17/07 Telescoping joints for varying drill string lengths; Shock absorbers
• CPC Class Codes: E21B 17/073 with axial rotation
• CPC Class Codes: E21B 17/10 Wear protectors; Centralising devices , e.g. stabilisers
• CPC Class Codes: E21B 17/1014 Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well E21B17/1042 takes precedence
• CPC Class Codes: E21B 17/1078 Stabilisers or centralisers for casing, tubing or drill pipes devices for off-center positioning E21B17/10; E21B17/1007 - E21B17/1064 take precedence
• CPC Class Codes: E21B 41/0085 Adaptations of electric power generating means for use in boreholes

Abstract

A downhole assembly for insertion into a borehole comprising an articulated mandrel, a passive and an active damping mechanism operating on said mandrel for exercising control over torsional stick-slip and further proposing an improvement over the prior art which diminishes lateral shock.

Claims

1. A downhole assembly for insertion into a borehole comprising a stabilizer sleeve element radially collocated about a bi-partite mandrel having an articulating and compliant metal-to-metal point of torque transfer, said stabilizer sleeve having passive and active damping mechanisms associated therewith operating upon said bi-partite mandrel and located about said articulating and compliant metal-to-metal point of torque transfer.

2. The downhole assembly according to claim 1, wherein said active damping mechanism acts in a direction with a component substantially perpendicular to the axis of the borehole.

3. The downhole assembly according to claim 1, wherein said active damping mechanism comprises a hydraulic damping mechanism.

4. The downhole assembly according to claim 3, wherein said hydraulic damping mechanism comprises a plurality of piston sub-assemblies each configured as a pair of pistons acting on said bi-parte mandrel, wherein said paired pistons of each piston sub-assembly are in fluid communication with one another.

5. The downhole assembly according to claim 4, wherein hydraulic fluid is transferred between paired pistons in each piston sub-assembly in a closed hydraulic loop.

6. The downhole assembly according to claim 5, wherein in each piston sub-assembly said two pistons are spaced axially at differing positions along said bi-parte mandrel.

7. The downhole assembly according to claim 4 further comprising electro-mechanical or electro-hydraulic valve means and, wherein said electro-mechanical or electro-hydraulic valve means are configured to control the flow of fluid between said piston pairs within each piston sub-assembly.

8. The downhole assembly according to claim 1, wherein said active damping mechanism comprises resilient material.

9. The downhole assembly according to claim 1 wherein said damping mechanisms comprise electro-mechanical or electro-hydraulic valve means.

10. The downhole assembly according to claim 1, wherein the active damping mechanism comprises rheological materials.

11. The downhole assembly according to claim 10, further comprising magnets configurable to influence the properties of said rheological materials.

12. The downhole assembly according to claim 1, wherein said active and passive damping means are configured to provide lateral, axial and torsional damping.

13. The downhole assembly according to claim 1, further comprising a stabilizer member configured to center said assembly in a borehole, said stabilizer comprising a plurality of blades and configured to provide energy dissipation to said borehole wall.

14. The downhole assembly according to claim 13, wherein said active damping mechanism is at least partially housed in at least one of said blades.

15. The downhole assembly according to claim 1, wherein the relative motion has a component lateral to the axis of the bore hole.

16. The downhole assembly according claim 1, further comprising piezo electric members configured to convert vibrations in said assembly into an electrical output.

17. The downhole assembly according to claim 16, wherein said electrical output provides power for said active damping mechanism proportional to any one of input vibration amplitude or frequency.

18. The downhole assembly according to claim 16, adapted to use the output from the piezo electric members for measurement, as a means of quantifying forces to be applied or as an actuation motive means within the device.

19. The downhole assembly according claim 1, further comprising a torque transfer mechanism and a resilient fluid passageway adapted to provide intra-structural support thereby serving to isolate said torque transfer mechanism and said active vibration damping mechanism from drilling fluids.

20. The downhole assembly according claim 1, further comprising receiving means configured to receive information from sensors located within said downhole assembly.

21. The downhole assembly according claim 20, wherein said receiving means is configured to receive information from a plurality of locations within the environ of the borehole or on said downhole assembly.

22. A method of controlling vibration in a downhole assembly said method comprising;

providing a stabilizer sleeve element radially collocated about a bi-partite mandrel having an articulating and compliant metal-to-metal point of torque transfer in a borehole; and

both passively and actively damping said bi-partite mandrel about said articulating and compliant metal-to-metal point of torque transfer.

23. The method according to claim 22, wherein the damping capability is modifiable and variable in both frequency and amplitude, responsive to harmonic vibration encountered in the environs of a drill bit in communication with said articulated bi-partite mandrel.

24. The method according to claim 22, wherein said damping is hydraulic and hydraulic actuation is proportional, continuous, discontinuous, intermittent or sporadic in response to particular harmonic vibration encountered by said articulated bi-partite mandrel located in the environs of a drill bit.