Degradable elements for downhole applications

Patent metadata

Field	Value
Publication number	US-10358887-B2
Application number	US-201615340166-A
Country	US
Kind code	B2
Filing date	Nov 1, 2016
Priority date	Nov 1, 2016
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

A downhole element for use in a wellbore with a wellbore fluid. The downhole element includes a body formed from a dissolvable material to degrade at a first rate when exposed to the wellbore fluid, with at least one cavity defined by the body. A degradation agent is disposed within the at least one cavity. The at least one cavity selectively releases the degradation agent and the degradation agent degrades the body at a second rate when exposed to the wellbore fluid and the dissolvable material.

First claim

What is claimed is:

1. A frac plug for use in a wellbore with a wellbore fluid, the frac plug comprising:
a body of the frac plug formed from a dissolvable material to degrade at a first rate when exposed to the wellbore fluid;
at least one cavity defined by the body; and
a degradation agent disposed within the at least one cavity, wherein the at least one cavity selectively releases the degradation agent and the degradation agent degrades the body at a second rate when exposed to the wellbore fluid and the dissolvable material.

2. The downhole element of claim 1 , wherein the cavity is defined by at least one wall of the body.

3. The downhole element of claim 2 , wherein the at least one wall includes a reduced thickness portion.

4. The downhole element of claim 1 , wherein the degradation agent is a dry acid.

5. The downhole element of claim 4 , wherein the dry acid is at least one of boric acid, sodium bisulfate, oxalic acid, sulfamic acid, and phthalic acid.

6. The downhole element of claim 1 , wherein the degradation agent is disposed within a breakable container.

7. The downhole element of claim 6 , wherein the breakable container is broken by movement of the body.

8. The downhole element of claim 1 , wherein movement of the body releases the degradation agent from the cavity.

9. The downhole element of claim 8 , wherein the body translates to open the cavity.

10. The downhole element of claim 9 , wherein the body is selectively retained.

11. The downhole element of claim 10 , wherein the body is selectively retained by a shear device.

12. A method to accelerate degradation in a wellbore with a wellbore fluid, the method comprising:
defining at least one cavity within a body of a frac plug wherein the body is formed from a dissolvable material;
disposing a degradation agent within the at least one cavity;
exposing the frac plug to the wellbore fluid;
degrading the body at a first rate in response to the wellbore fluid;
selectively releasing the degradation agent from the cavity;
exposing the degradation agent to the wellbore fluid and the dissolvable material; and
degrading the dissolvable material at a second rate in response to the wellbore fluid.

13. The method of claim 12 , wherein the degradation agent is a dry acid.

14. The method of claim 13 , wherein the dry acid is at least one of boric acid, sodium bisulfate, oxalic acid, sulfamic acid, and phthalic acid.

15. The method of claim 12 , wherein the degradation agent is disposed within a breakable container.

16. The method of claim 15 , wherein the breakable container is broken by movement of the body.

17. The method of claim 16 , wherein movement of the body releases the degradation agent from the cavity.

18. A system for use in a wellbore with a wellbore fluid, the system comprising:
a casing string disposed within the wellbore; and
a frac plug disposed within the casing string, the frac plug including:
a body formed from a dissolvable material to degrade at a first rate when exposed to the wellbore fluid;
at least one cavity defined by the body; and
a degradation agent disposed within the at least one cavity, wherein the at least one cavity selectively releases the degradation agent and the degradation agent degrades the body at a second rate when exposed to the wellbore fluid and the dissolvable material.

Assignees

• Wise Tristan
• Doane James
• Yuan Yusheng
• Baker Hughes A Ge Co Llc

Inventors

• Wise Tristan
• Doane James
• Yuan Yusheng

Classifications

• E21B29/00

  Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground · CPC title

• E21B43/126

  Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive (powered by fluid E21B43/129) · CPC title

• E21B33/12 Primary

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

• E21B43/26

  by forming crevices or fractures · CPC title

• E21B2200/08

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