HIGH PRESSURE AND HIGH TEMPERATURE BALL SEAT

• US 20110259610A1
• Filed: 04/21/2011
• Published: 10/27/2011
• Est. Priority Date: 04/23/2010
• Status: Active Grant

• Current Assignee: Smith International Incorporated (Schlumberger NV)
• Original Assignee: Smith International Incorporated (Schlumberger NV)
• Inventors: WOLF, John C., SHKURTI, Piro
• Granted Patent: US 9,045,963 B2
• Time in Patent Office: Days
• US Class Current: 166/386
• CPC Class Codes: E21B 2200/04 Ball valves
• CPC Class Codes: E21B 33/12 Packers; Plugs used for cementing E21B33/134, E21B33/16
• CPC Class Codes: E21B 33/1204 permanent; drillable
• CPC Class Codes: E21B 33/1216 Anti-extrusion means, e.g. means to prevent cold flow of rubber packing
• CPC Class Codes: E21B 33/1285 by fluid pressure
• CPC Class Codes: E21B 33/1295 actuated by fluid pressure

Abstract

An isolation device for a frac plug, the isolation device including a ball seat having a seating surface and a ball configured to contact the seating surface, wherein a profile of the seating surface corresponds to a profile of the ball. A frac plug including a mandrel having an upper end and a lower end, a sealing element disposed around the mandrel, and a ball seat disposed within a central bore of the mandrel, wherein the ball seat includes a seating surface having a non-linear profile. A method of isolating zones of a production formation, the method including setting a frac plug between a first zone and a second zone, disposing a ball within the frac plug, and seating a ball in a ball seat of the frac plug, the ball seat including a seating surface having a profile that substantially corresponds to the profile of the ball.

Claims

1. An isolation device for a frac plug, the isolation device comprising:

a ball seat having a seating surface; and

a ball configured to contact the seating surface;

wherein a profile of the seating surface corresponds to a profile of the ball.

2. The isolation device of claim 1, wherein the profile of the seating surface is arcuate.

3. The isolation device of claim 1, wherein the radius of curvature of the profile of the seating surface is substantially equal to the radius of curvature of the profile of the ball.

4. The isolation device of claim 1, wherein the profile of the seating surface comprises at least two discrete sections.

5. The isolation device of claim 4, wherein at least one discrete section comprises a linear profile.

6. The isolation device of claim 5, wherein the angle of a first discrete section with respect to a center axis of the ball seat is different from the angle of a second discrete section.

7. The isolation device of claim 4, wherein at least one discrete section comprises an arcuate profile.

8. The isolation device of claim 7, wherein the radius of curvature of a first discrete section is different from a radius of curvature of a second discrete section.

9. The isolation device of claim 1, wherein the ball seat further comprises a first section disposed axially above the seating surface, wherein the first section comprises a tapered profile.

10. The isolation device of claim 1, wherein the ball comprises a phenolic resin and glass fiber.

11. The isolation device of claim 1, wherein the ball seat is formed from aluminum.

12. A frac plug comprising:

a mandrel having an upper end and a lower end;

a sealing element disposed around the mandrel; and

a ball seat disposed within a central bore of the mandrel,

wherein the ball seat comprises a seating surface having a non-linear profile.

13. The frac plug of claim 12, wherein the seating surface comprises an arcuate profile.

14. The frac plug of claim 12, wherein the wherein the non-linear profile of the seating surface comprises at least two discrete sections.

15. The frac plug of claim 14, wherein at least one discrete section comprises a linear profile.

16. The frac plug of claim 14, wherein at least one discrete section comprises an arcuate profile.

17. A method of isolating zones of a production formation, the method comprising:

running a frac plug downhole to a determined location between a first zone and a second zone;

setting the frac plug between the first zone and the second zone;

disposing a ball within the frac plug; and

seating a ball in a ball seat of the frac plug, the ball seat comprising a seating surface having a profile that substantially corresponds to the profile of the ball.

18. The method of claim 17, further comprising increasing a pressure differential across the ball and ball seat.

19. The method of claim 17, wherein the profile of the seating surface is arcuate.

20. The method of claim 17, wherein the profile of the seating surface comprises at least two discrete sections.