WO1998054438B1

WO1998054438B1 - Bottomhole assembly orienting sub

Info

Publication number: WO1998054438B1
Application number: PCT/US1998/010488
Authority: WO
Filing date: 1998-05-22
Publication date: 1999-02-04

Abstract

A mechanism for orienting and maintaining a key (30) in a sub (24) for guiding directional measurement equipment of a directional drilling assembly with respect to a drill bit. The orienting sub (24) has an outer sleeve (34) which is supported on an inner shoulder (33) in the orienting sub (24). An inner sleeve (48) which holds the key (30) has an outer wedged profile which follows the shape of the outer sleeve (34). The outer sleeve (34) can be longitudinally, obliquely, or spirally segmented and has a thread (44) on one end so that a jam nut (46) can be installed to advance the inner sleeve (48) with the key (30) until a wedging action occurs between the inner and outer sleeves and the sub (30). Provisions can be made in the assembly to provide a biasing force (60) on the inner sleeve (48) which holds the key (30) to compensate for vibrational loads on the assembly.

Claims

AMENDED CLAIMS[received by the International Bureau on 11 December 1998 (11.12.98); original claims 1 and 19 amended; remaining claims unchanged (5 pages)]

1. An orientation key assembly for an orientation sub used in directional drilling and having an internal surface, comprising: a key sleeve having a longitudinal axis and an orienting key extending therefrom; a fastening assembly securable from within the orienting sub to secure said key sleeve to the internal surface of said orienting sub by a wedging action, said wedging action applying a force to said key sleeve substantially perpendicular to said longitudinal axis to secure it to the orientation sub.

2. The assembly of claim 1 , wherein: said fastening assembly further comprises a second sleeve, said second sleeve configured to be radially expandable; said key and second sleeves having tapers such that relative axial movement between them results in a radial expansion of said second sleeve, resulting in a wedging of said key sleeve in the orienting sub.

3. The assembly of claim 2, wherein: said second sleeve is mounted externally to said key sleeve such that said wedging action pushes said key sleeve against said second sleeve, which in turn expands against the orientating sub.

4. The assembly of claim 3, wherein: said second sleeve comprises a threaded portion which accom- modates a nut;

16 said nut when rotated advances against said key sleeve to force said tapers against the each other.

5. The assembly of claim 4, wherein: said nut is formed having an opening therethrough; said fastening assembly further comprises a tool that extends through said nut which can retain said key against rotation while turning said nut.

6. The assembly of claim 5, wherein: said tool comprises first and second tubes, with said first tube having a slot to accept said key and a handle aligned with said slot to indicate its orientation, said second tube configured to engage said nut to turn it while said first tube is held stationary.

7. The assembly of claim 6, wherein: said second sleeve has a longitudinal axis and is split to facilitate its radial expansion in the orienting sub.

8. The assembly of claim 7, wherein: said split is substantially longitudinal.

9. The assembly of claim 7, wherein: said split is in the form of a spiral.

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10. The assembly of claim 7, further comprising: a biasing member between said nut and said key sleeve.

11. The assembly of claim 10, wherein: said second sleeve comprises a lower end which engages the orienting sub so as to limit further longitudinal movement thereof in one direction.

12. The assembly of claim 1 , wherein: said fastening assembly further comprises a nut and a tool capable of holding said key in a predetermined position, while at the same time advancing said nut to initiate said wedging action.

13. The assembly of claim 12, wherein: said tool extends through said nut and is multi-component.

14. The assembly of claim 13, further comprising: a second sleeve mounted between said key sleeve and the orienting sub, said sleeves having facing tapers which are forced against each other when said tool advances said nut.

15. The assembly of claim 14, wherein: said tool comprises first and second concentric tubes, with said first tube having a slot to accept said key and a handle aligned with said slot to indicate its orientation, said second tube configured to engage said nut to turn it while said first tube is held stationary.

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16. The assembly of claim 15, wherein: said second sleeve is split to facilitate its radial expansion in the orienting sub.

17. The assembly of claim 16, further comprising: a biasing member between said nut and said key sleeve.

18. The assembly of claim 17, wherein: said second sleeve comprises a lower end which engages the orienting sub so as to limit further longitudinal movement thereof in one direction.

19. In combination, an orienting sub for directional drilling, having an internal surface, a longitudinal axis, and a key sleeve having a key thereon, wherein said key sleeve is secured to said internal surface of said orienting sub by a wedging action, said wedging action applying a force to said key sleeve substantially perpendicular to said longitudinal axis to secure it to the orientation sub.

20. The combination of claim 19, wherein: said key sleeve has a taper and said orienting sub has a taper and a thread with a nut; said key sleeve is split so as to allow it to contract into locking engagement with said orienting sub as said nut is advanced toward it.

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21. The combination of claim 19, further comprising: an outer sleeve having a taper thereon; said key sleeve having a conforming taper to said taper on said outer sleeve; said outer sleeve having a split and a threaded nut such that advancement of said nut forces said tapers together as said key sleeve moves axially with respect to said outer sleeve and, due to said split, said outer sleeve is further forced against said orienting sub.

22. The combination of claim 21 , wherein: said nut is formed having an opening to allow access there- through to a tool, said tool holding said key while rotating said nut to force said tapers against each other.

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