Multi-use tubing disconnect

• US 6,408,946 B1
• Filed: 04/28/2000
• Issued: 06/25/2002
• Est. Priority Date: 04/28/2000
• Status: Expired due to Fees

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Hart, Daniel R., Marshall, Gregory S.
• Primary Examiner(s): SUCHFIELD, GEORGE A
• Application Number:
  US09/561,484
• Time in Patent Office: 788 Days
• Field of Search: 166/242.1, 166/242.6, 166/242.7, 166/317, 166/318, 166/376, 166/377, 166/378, 166/381
• US Class Current: 166/317
• CPC Class Codes: E21B 17/06 Releasing-joints, e.g. safety joints
• CPC Class Codes: E21B 23/042 using a single piston or multiple mechanically interconnected pistons

Abstract

An apparatus for disconnecting a bottom hole assembly from a work string, having an upper tool body, a piston biased away from a slidable collet, locking dogs held in engagement with a lower tool body by the slidable collet, and one or more collet fingers holding the collet in place, relative to the upper body. The piston can be hydraulically displaced against the biasing spring, thereby releasing the collet finger, followed by further displacement of the piston to contact the collet, then displacement of the piston and the collet to release the locking dogs from engagement with the lower tool body. A shear pin in the collet can provide a positive pressure indication of release of the disconnect device.

Claims

1. A disconnect device for downhole use in oil or gas wells, comprising:

an upper tool body;

a dog housing mountable to said upper body;

a lower tool body;

at least one movable dog cried by said dog housing;

a collet adapted to selectively maintain said at least one dog in engagement with said lower body, thereby preventing longitudinal movement of said lower body relative to said dog housing; and

a piston slidably mounted at an initial position relative to said dog housing, wherein said piston is not in abutment with said collet,

wherein said piston is hydraulically movable from said initial position to a second position in which said piston abuts said collet to move said collet longitudinally relative to said dog housing to release said at least one dog from engagement with said lower body.

2. The disconnect device recited in claim 1, further comprising at least one shear pin attaching said collet to said dog housing, wherein said piston moves said collet longitudinally to shear said at least one shear pin and then to release said at least one dog from engagement with said lower body.

3. The disconnect device recited in claim 1, further comprising a capture element on said collet for longitudinally capturing said collet relative to said dog housing to maintain said at least one dog in engagement with said lower body.

4. The disconnect device recited in claim 3, wherein:

said capture element comprises a finger on said collet;

said piston is adapted to hold said collet finger longitudinally stationary relative to said upper body in said initial position of said piston; and

said piston is adapted to release said collet finger upon movement of said piston from said initial position.

5. The disconnect device recited in claim 1, further comprising at least one dog cavity on said lower body for receiving said at least one dog, to prevent relative longitudinal motion between said dog housing and said lower body.

6. The disconnect device recited in claim 1, further comprising a biasing device adapted to bias said piston away from said collet.

7. The disconnect device recited in claim 6, wherein said biasing device comprises a spring arranged between said piston and said collet.

8. A disconnect device for downhole use in oil or gas wells, comprising:

an upper tool body;

a dog housing mountable to said upper body;

a lower tool body;

at least one movable dog carried by said dog housing;

a collet adapted to selectively maintain said at least one dog in engagement with said lower body, thereby preventing longitudinal movement of said lower body relative to said dog housing;

at least one shear pin attaching said collet to said dog housing; and

a piston slidably mounted at an initial position relative to said dog housing,

wherein said piston is not in abutment with said collet;

wherein said piston is hydraulically movable from said initial position to a second position in which said piston abuts said collet to shear said at least one shear pin, and to then move said collet longitudinally relative to said dog housing to release said at least one dog from engagement with said lower body.

9. The disconnect device recited in claim 8, further comprising a capture element on said collet for longitudinally capturing said collet relative to said dog housing, preventing inadvertent application of shear force to said at least one shear pin.

10. The disconnect device recited in claim 9, wherein:

said capture element comprises a finger on said collet;

said piston is adapted to hold said collet finger longitudinally stationary relative to said upper body in said initial position of said piston; and

said piston is adapted to release said collet finger upon movement of said piston from said initial position.

11. The disconnect device recited in claim 8, further comprising at least one dog cavity on said lower body for receiving said at least one dog, to prevent relative longitudinal motion between said dog housing and said lower body.

12. The disconnect device recited in claim 8, further comprising a biasing device adapted to bias said piston away from said collet.

13. The disconnect device recited in claim 12, wherein said biasing device comprises a spring arranged between said piston and said collet.

14. The disconnect device recited in claim 8, further comprising a seat on said piston, said seat being adapted to receive a setting ball to increase hydraulic force on said piston.

15. The disconnect device recited in claim 8, further comprising at least one seal adapted to prevent flow of working fluid past said dog.

16. The disconnect device recited in claim 15, wherein said seal is adapted to prevent flow of working fluid between said dog housing and said collet.

17. The disconnect device recited in claim 16, further comprising a fluid bypass device adapted to relieve fluid pressure between said dog housing and said collet, thereby allowing movement of said collet relative to said dog housing.

18. The disconnect device recited in claim 17, wherein said fluid bypass device comprises a weep valve.

19. The disconnect device recited in claim 8, further comprising an overpressure device adapted to selectively establish flow between the interior of said disconnect device and a well bore annulus surrounding said disconnect device.

20. The disconnect device recited in claim 19, wherein said overpressure device comprises a rupture disk.

21. The disconnect device recited in claim 8, further comprising an adjusting sleeve adapted to bias said lower body away from said dog housing, to prevent loose assembly points.

22. The disconnect device recited in claim 21, wherein:

said adjusting sleeve threadedly engages one of said dog housing and said lower body; and

said adjusting sleeve abuts the other of said dog housing and said lower body.

23. A disconnect device for downhole use in oil or gas wells, comprising:

an upper tool body;

a locking device mountable to said upper body;

a lower tool body;

a collet adapted to selectively maintain said locking device in engagement with said lower body, thereby preventing longitudinal movement of said lower body relative to said upper body;

at least one shear pin preventing longitudinal movement of said collet relative to said upper body;

a capture element on said collet for longitudinally capturing said collet relative to said upper body, preventing inadvertent application of shear force to said at least one shear pin; and

a piston slidably mounted at an initial position relative to said upper body,

wherein said piston is not in abutment with said collet;

wherein said piston is hydraulically movable from said initial position to a second position in which said piston abuts said collet to shear said at least one shear pin, and to then move said collet longitudinally relative to said upper body to release said locking device from engagement with said lower body.

24. The disconnect device recited in claim 23, further comprising a biasing device adapted to bias said piston away from said collet.

25. The disconnect device recited in claim 24, wherein said biasing device comprises a spring arranged between said piston and said collet.