DRILLABLE PLUG

• US 20150021042A1
• Filed: 07/17/2014
• Published: 01/22/2015
• Est. Priority Date: 07/19/2013
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Melenyzer, George J., Cromer, Christopher
• Granted Patent: US 10,450,829 B2
• Time in Patent Office: Days
• US Class Current: 166/376
• CPC Class Codes: E21B 33/1204 permanent; drillable
• CPC Class Codes: E21B 33/134 Bridging plugs

Abstract

A drillable plug includes a mandrel having an upper end and a lower axial section, the lower axial section having a geometry transition point separating an upper circular mandrel profile from a lower non-circular mandrel profile, a seal element disposed around the upper circular mandrel profile, and a lower cone having an inner surface forming a passage, the lower cone disposed around the lower non-circular mandrel profile whereby the lower cone is rotationally locked with the mandrel and a lower slip assembly moveably disposed on a sloped outer surface of the lower cone.

Claims

1. A drillable plug, comprising:

a mandrel having a top end and a lower axial section, wherein the lower axial section comprises a geometry transition point separating an upper circular mandrel profile from a lower non-circular mandrel profile;

a seal element disposed around the upper circular mandrel profile;

a lower cone having an inner surface forming a passage, the lower cone disposed around the lower non-circular mandrel profile whereby the lower cone is rotationally locked with the mandrel; and

a lower slip assembly moveably disposed on a sloped outer surface of the lower cone.

2. The drillable plug of claim 1, wherein the passage comprises a circular section and a non-circular section.

3. The drillable plug of claim 1, wherein the passage comprises a circular section disposed about the upper circular mandrel profile and a non-circular section disposed around the lower non-circular mandrel profile.

4. The drillable plug of claim 1, wherein the seal element comprises an end ring connected to a lower end of the seal element and comprising an axially extending member connectable with the lower cone.

5. The drillable plug of claim 1, wherein the lower cone comprises a recess formed along the inner surface;

and

the seal element comprises an end ring connected to a lower end of the seal element and comprising an axially extending member disposed in the recess.

6. The drillable plug of claim 1, wherein the sloped outer surface is positioned in a groove between opposing side walls.

7. The drillable plug of claim 1, further comprising:

an upper gage ring disposed around the mandrel adjacent the top end;

an upper cone disposed around the upper circular mandrel profile between the upper gage ring and the seal element; and

an upper slip assembly moveably disposed on a sloped outer surface of the upper cone, wherein the sloped outer surface is positioned in a groove between opposing side walls.

8. The drillable plug of claim 1, further comprising:

an upper gage ring disposed around the mandrel adjacent the top end;

an upper cone disposed around the upper circular mandrel profile between a lower face the upper gage ring and the seal element; and

an upper slip assembly comprising an upper end and a slip base, the upper end rotationally locked with the upper gage ring and the slip base moveably disposed on a sloped outer surface of the upper cone.

9. The drillable plug of claim 1, further comprising:

an upper gage ring disposed around the mandrel adjacent the top end and having a lower face forming a pocket;

an upper cone disposed around the upper circular mandrel profile between the lower face and the seal element; and

an upper slip assembly comprising an upper end and a slip base, the upper end positioned in the pocket and the slip base moveably disposed on a sloped outer surface, wherein the sloped outer surface is located between opposing side walls.

10. A method, comprising:

milling or drilling through a drillable plug that is set in a wellbore, the drillable plug comprising;

a mandrel having a top end and a lower axial section, wherein the lower axial section comprises a geometry transition point separating an upper circular mandrel profile from a lower non-circular mandrel profile;

an upper gage ring disposed around the mandrel adjacent the top end;

a seal element disposed around the upper circular mandrel profile;

an upper cone disposed around the upper circular mandrel profile between the upper gage ring and the seal element;

an upper slip assembly moveably disposed on a sloped outer surface of the upper cone;

a lower cone having an inner surface forming a passage, the lower cone disposed around the lower non-circular mandrel profile whereby the lower cone is rotationally locked with the mandrel; and

a lower slip assembly moveably disposed on a sloped outer surface of the lower cone.

11. The method of claim 10, wherein the passage comprises a circular section and a non-circular section.

12. The method of claim 10, wherein the passage comprises a circular section disposed about the upper circular mandrel profile and a non-circular section disposed around the lower non-circular mandrel profile.

13. The method of claim 10, wherein the seal element comprises an end ring connected to a lower end of the seal element and comprising an axially extending member connectable with the lower cone.

14. The method of claim 10, wherein the lower cone comprises a recess formed along the inner surface;

and

the seal element comprises an end ring connected to a lower end of the seal element and comprising an axially extending member disposed in the recess.

15. The method of claim 10, wherein the sloped outer surface of the upper cone is positioned in a groove between opposing side walls and the sloped outer surface of the lower cone is positioned in a groove between opposing side walls.

16. The method of claim 10, wherein the upper slip assembly comprises an upper end and a slip base, the upper end rotationally locked with the upper gage ring and the slip base is moveably disposed on the sloped outer surface of the upper cone.

17. The method of claim 16, wherein the sloped outer surface of the upper cone is disposed in a groove disposed between opposing side walls.

18. The method of claim 10, wherein the upper gage ring comprises a lower face forming a pocket;

and

the upper slip assembly comprises an upper end and a slip base, the upper end positioned in the pocket and the slip base moveably disposed on the sloped outer surface of the upper cone, wherein the sloped outer surface of the upper cone is located between opposing side walls.

19. A drillable plug, comprising:

a mandrel having a top end and a lower axial section, wherein the lower axial section comprises a geometry transition point separating an upper circular mandrel profile from a lower non-circular mandrel profile;

an upper gage ring disposed around the mandrel adjacent the top end;

a seal element disposed around the upper circular mandrel profile;

an upper cone disposed around the upper circular mandrel profile between the upper gage ring and the seal element;

an upper slip assembly moveably disposed on a sloped outer surface of the upper cone that is disposed between opposing side walls;

a lower cone having an inner surface forming a passage comprising a circular section disposed about the upper circular mandrel profile and a non-circular section disposed around the lower non-circular mandrel profile whereby the lower cone is rotationally locked with the mandrel;

a lower slip assembly moveably disposed on a sloped outer surface of the lower cone that is disposed between opposing side walls; and

an end ring connected to a lower end of the seal element and comprising an axially extending member disposed in a recess formed in the inner surface of the lower cone.

20. The drillable plug of claim 19, wherein the upper gage ring comprises a lower face forming a pocket;

and

the upper slip assembly comprises an upper end and a slip base, the upper end positioned in the pocket and the slip base moveably disposed on the sloped outer surface of the upper cone.