Kobe sub, wellbore tubing string apparatus and method

Patent metadata

Field	Value
Publication number	US-9366109-B2
Application number	US-201313893656-A
Country	US
Kind code	B2
Filing date	May 14, 2013
Priority date	Nov 19, 2010
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

To address concerns of kobe plug cap portions being inadvertently removed, for example, by abutment with strings or tools passing thereby, a shielding structure may be employed to protect the cap against inadvertent removal. The port opening tool useful with the kobe plug is selected to overcome the shielding structure to open the kobe plug. To address concerns of a portion of the kobe plug becoming loose in the tubing string inner bore, a capturing mechanism may be provided that captures the cap portion after it is removed to open the kobe plug and prevented the cap portion from becoming loose in the inner bore of the tubing string.

First claim

We claim:

1. A kobe sub comprising: a tubular body connectable into a wellbore tubing string, the tubular body including a wall including an outer surface and an inner surface defining an inner bore and a port through the wall; a kobe plug installed in the port including a base mounted in the port, a cap portion accessible in the inner bore and connected to the base and a channel extending through the base and closed by the cap portion, the cap portion being removable from the base to open the channel to allow fluid passage though the channel from the inner bore to the outer surface; and a capturing mechanism to capture the cap portion from becoming loose in the inner bore after the cap portion is removed from a sealing position on the base.

2. The kobe sub of claim 1 wherein the capturing mechanism causes the cap portion to be pushed outwardly into the channel toward the outer surface.

3. The kobe sub of claim 1 wherein the cap portion breaks outwardly into the channel and is pushed out by fluid flow through the channel.

4. The kobe sub of claim 1 wherein the cap portion is a plug installed in the channel and the channel is tapered inwardly to a diameter less than the plug to prevent the plug from becoming loose in the inner bore.

5. The kobe sub of claim 1 wherein the capturing mechanism stores the cap portion in the sub.

6. The kobe sub of claim 1 wherein the capturing mechanism includes a hinge between the cap portion and the base that secures the cap portion to the base after the cap portion is removed from a sealing position on the base.

7. The kobe sub of claim 1 wherein the capturing mechanism includes an extension of the wall inner surface overlying a portion of the cap portion that retains the cap portion after the cap portion is removed from a sealing position on the base.

8. The kobe sub of claim 1 wherein the kobe plug is positioned in a slot formed in the inner surface and the capturing mechanism includes a return overlying a portion of the cap portion to prevent the cap portion from passing out of the slot after the cap portion is removed from a sealing position on the base.

9. The kobe sub of claim 1 wherein the capturing mechanism includes a sleeve installed in the inner bore and positioned to overlie at least a portion of the cap portion and including a cavity in the sleeve that retains the cap portion after the cap portion is removed from a sealing position on the base.

10. The kobe sub of claim 9 wherein the sleeve overlies the cap portion and the cavity is an indentation in an underside of the sleeve.

11. The kobe sub of claim 9 wherein the sleeve is moveable to abut against the cap portion to remove the cap portion from a sealing position on the base.

12. The kobe sub of claim 9 wherein the sleeve includes a shoulder against which a port opening tool pushes to move the sleeve.

13. The kobe sub of claim 12 wherein the shoulder is a ball seat and the port opening tool is a plug sized to land and seal in the ball seat.

14. The kobe sub of claim 1 wherein the capturing mechanism collects the cap portion in a port opening tool.

15. The kobe sub of claim 1 further comprising a shielding structure in the inner bore to shield the cap portion from protruding unprotected into the inner bore.

16. The kobe sub of claim 15 wherein the shielding structure includes a shielding wall extending alongside the cap portion.

17. The kobe sub of claim 16 wherein the shielding wall is a sidewall of a slot formed in the wall inner surface.

18. The kobe sub of claim 17 wherein the sidewall defines a slot depth and the slot depth is greater than the height of the cap portion such that the cap portion is fully recessed in the slot.

19. The kobe sub of claim 17 wherein the slot includes a return overlying a portion of the cap portion.

20. The kobe sub of claim 16 wherein the shielding wall includes an extension of the wall inner surface overlying a portion of the cap portion.

21. The kobe sub of claim 15 wherein the shielding structure is a sleeve installed in the inner bore and positioned to overlie at least a portion of the cap portion.

22. The kobe sub of claim 1 further comprising a flow limiting device in the channel for at least restricting flow through the channel and for providing a delay before the port becomes fully open to fluid flow.

23. The kobe sub of claim 22 wherein the flow limiting device is removed by erosion.

24. A method for forming a fluid channel through a tubing string wall, the method comprising: installing a tubing string in a wellbore, the tubing string including a tubular wall including an outer surface and an inner surface defining an open inner bore and a port through the wall; and a kobe plug installed in the port including a base mounted in the port, a cap portion accessible in the inner bore and connected to the base and a channel extending through the base and closed by the cap portion, the cap portion being removable from the base to open the channel to allow fluid passage though the channel from the inner bore to the outer surface; introducing a port opening tool into the inner bore; manipulating the tool to remove the cap portion from a sealing positon on the base to open the channel; and capturing the cap portion to prevent the cap portion from becoming loose in the inner bore.

25. The method of claim 24 wherein capturing the cap portion includes collecting the cap portion in the tool after it is removed from the base.

26. The method of claim 24 further comprising a hinge between the cap portion and the base, manipulating the tool includes applying a force to break the cap portion away from the base to pivot the cap portion about the hinge and capturing includes storing the cap portion connected to the base through the hinge.

27. The method of claim 24 wherein capturing includes storing the cap portion in the tubing string.

28. The method of claim 27 further comprising an extension of the inner surface overlying a portion of the cap portion and storing includes storing the cap portion in a position retained by the extension after the cap portion is removed from a sealing position on the base.

29. The method of claim 27 further comprising a slot in which the kobe plug is positioned with a return overlying a portion of the cap portion and storing includes positioning the cap portion in a position retained by the return after it is removed from a sealing position on the base.

30. The method of claim 27 further comprising a slot in which the kobe plug is positioned with a return overlying a portion of the cap portion and storing includes moving the cap portion into a frictionally jammed position in the slot.

31. The method of claim 27 further comprising a slot in which the kobe plug is positioned with a return overlying a portion of the cap portion and storing includes moving the cap portion along the slot to a retaining cavity.

32. The method of claim 27 further comprising a sleeve installed in the inner bore and positioned to overlie at least a portion of the cap portion and storing includes retaining the cap portion in a position under the sleeve after the cap portion is removed from a sealing position on the base.

33. The method of claim 24 further comprising a sleeve installed in the inner bore and wherein manipula

Assignees

• Packers Plus Energy Serv Inc

Inventors

• Themig Daniel Jon
• Desranleau Christopher Denis
• Coon Robert Joe

Classifications

• E21B34/063 Primary

  Valve or closure with destructible element, e.g. frangible disc (E21B34/103 takes precedence) · CPC title

• E21B34/14 Primary

  operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools {(E21B34/066 takes precedence)} · CPC title