Buoyancy assist tool with debris barrier

Patent metadata

Field	Value
Publication number	US-10995583-B1
Application number	US-201916670567-A
Country	US
Kind code	B1
Filing date	Oct 31, 2019
Priority date	Oct 31, 2019
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug includes a frangible disk. A stretchable connecting ring is connected to the frangible disk and to the casing.

First claim

What is claimed is:

1. A downhole apparatus comprising:
a casing string;
a degradable plug positioned in the casing string to block flow therethrough;
a flow barrier positioned in the casing string below the degradable plug, the degradable plug and the flow barrier defining a buoyancy chamber therebetween; and
a debris barrier positioned above the degradable plug, the debris barrier comprising:
a frangible disk configured to break into pieces and pass through the casing string upon removal of the plug from the casing string; and
a stretchable connecting ring connected to the frangible disk and to the casing string, the debris barrier and degradable plug defining a fluid chamber containing a fluid therebetween.

2. The downhole apparatus of claim 1 , the fluid in the fluid chamber comprising a degrading fluid.

3. The downhole apparatus of claim 2 , further comprising a plug housing connected in the casing string, the degradable plug fixed in the plug housing.

4. The downhole apparatus of claim 2 , further comprising a membrane positioned across an upper end of the degradable plug.

5. The downhole apparatus of claim 2 , the stretchable ring comprising an elastomeric ring.

6. The downhole apparatus of claim 2 , the stretchable ring configured to tear and disconnect the debris barrier from the casing string.

7. A downhole apparatus comprising:
an outer case connected at upper and lower ends in a casing string;
a degradable plug positioned in the outer case;
a flow barrier connected in the casing string below the degradable plug, the degradable plug and flow barrier defining a buoyancy chamber therebetween; and
a debris barrier mounted in the outer case above the degradable plug, the debris barrier comprising a frangible disk and a flexible connecting ring connecting the frangible disk to the outer case, the debris barrier and degradable plug defining a fluid chamber therebetween.

8. The downhole apparatus of claim 7 , further comprising:
a plug housing connected in the outer case, the plug housing and the outer case defining an annulus therebetween; and
a rupture disk positioned in a port defined in the outer case, the port positioned to communicate fluid from the fluid chamber into the annulus, the plug housing having openings therethrough to communicate the fluid to the degradable plug, the flexible connecting ring configured to tear and disconnect the frangible disk from the outer case after the rupture disk ruptures.

9. The downhole apparatus of claim 8 , the frangible disk configured to break into small fragments after the flexible connecting ring tears away from the outer case.

10. The downhole apparatus of claim 7 , the flexible connecting ring comprising an elastomeric connecting ring.

11. The downhole apparatus of claim 7 , the frangible disk comprising a dome-shaped frangible disk.

12. The downhole apparatus of claim 7 , the frangible disk comprising an upward-facing concave disk.

13. The downhole apparatus of claim 7 further comprising an impermeable membrane stretched across upper and lower ends of the degradable plug.

14. A downhole apparatus comprising:
a casing string;
an outer case connected to and forming a part of the casing string;
a plug housing connected in the outer case;
a degradable plug fixed in the outer case and positioned to block flow therethrough; and
a debris barrier connected in the casing string above the degradable plug, the debris barrier and degradable plug defining a fluid chamber containing a degrading fluid therebetween, the debris barrier comprising:
a flexible connecting ring; and
a frangible disk connected to the flexible connecting ring.

15. The downhole apparatus of claim 14 , further comprising a flow barrier connected in the casing string below the degradable plug, the degradable plug and flow barrier defining a buoyancy chamber therebetween.

16. The downhole apparatus of claim 14 , the flexible connecting ring configured to tear and disconnect the frangible disk from the outer case as a result of fluid pressure acting on the frangible disk.

17. The downhole apparatus of claim 16 , the outer case having a port communicated with an annulus defined by and between the plug housing and the outer case, the port having a rupture disk therein, the debris barrier configured to apply downward pressure to the fluid in the fluid chamber to rupture the rupture disk and urge the degrading fluid through the port.

18. The downhole apparatus of claim 14 , the flexible connecting ring comprising an elastomeric connecting ring.

19. The downhole apparatus of claim 18 , the frangible disk comprising a phenolic disk.

Assignees

• Halliburton Energy Services Inc

Inventors

• Helms Lonnie Carl
• Yuan Min Mark
• Ahuja Mayur Narain
• Patil Ishwar Dilip
• Parameshwaraiah Rajesh

Classifications

• E21B2200/08

  Down-hole devices using materials which decompose under well-bore conditions · CPC title

• E21B43/10 Primary

  Setting of casings, screens, liners {or the like} in wells · CPC title

• E21B34/06

  in wells · CPC title

• E21B33/12

  Packers; Plugs (used for cementing E21B33/134, E21B33/16) · CPC title

• E21B34/063 Primary

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