CORRODIBLE DOWNHOLE ARTICLE AND METHOD OF REMOVING THE ARTICLE FROM DOWNHOLE ENVIRONMENT

• US 20120318513A1
• Filed: 06/17/2011
• Published: 12/20/2012
• Est. Priority Date: 06/17/2011
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Mazyar, Oleg A., McCoy, Matthew T.
• Granted Patent: US 9,139,928 B2
• Time in Patent Office: Days
• US Class Current: 166/304
• CPC Class Codes: C23C 18/1637 metallic substrate
• CPC Class Codes: C23C 18/1689 After-treatment
• CPC Class Codes: C25D 5/48 After-treatment of electroplated surfaces
• CPC Class Codes: E21B 33/12 Packers; Plugs used for cementing E21B33/134, E21B33/16

Abstract

A method of removing a corrodible downhole article having a surface coating includes eroding the surface coating by physical abrasion, chemical etching, or a combination of physical abrasion and chemical etching, the surface coating comprising a metallic layer of a metal resistant to corrosion by a corrosive material.

Claims

1. A method of removing a corrodible downhole article having a surface coating, the method comprising:

eroding the surface coating by physical abrasion, chemical etching, or a combination of physical abrasion and chemical etching,

the surface coating comprising;

a metallic layer of a metal resistant to corrosion by a corrosive material.

2. The method of claim 1, the corrodible downhole article further comprising a corrodible core having the surface coating on a surface of the corrodible core.

3. The method of claim 2, wherein the corrodible core comprises magnesium alloy having less than or equal to about 0.5 weight percent of nickel.

4. The method of claim 1, wherein eroding is by physical abrasion alone.

5. The method of claim 1, wherein eroding comprises flowing a slurry of a proppant over the surface of the corrodible downhole article.

6. The method of claim 5, wherein the proppant includes sand, aluminum pellets, glass beads, ceramic beads, and combinations comprising at least one of the foregoing.

7. The method of claim 1, further comprising corroding the downhole article in the corrosive material after eroding.

8. The method of claim 7, wherein the corrosive material is water, brine, an acid, hydrogen sulfide, or a combination comprising at least one of the foregoing.

9. The method of claim 1, wherein the metallic layer has a thickness of less than or equal to about 1,000 micrometers.

10. The method of claim 1, wherein the metallic layer is formed by an electroless plating process, or by an electrodeposition process in the presence of an anhydrous ionic solvent.

11. The method of claim 10, wherein the metallic layer comprises nickel, aluminum, alloys thereof, or a combination comprising at least one of the foregoing.

12. The method of claim 1, wherein the corrodible downhole article is a ball seat or frac plug.

13. A method of forming a reversible seal with a corrodible downhole article, comprising

seating a ball or plug in the corrodible downhole article having a shaped surface which accommodates a surface shape of the ball or plug, the corrodible downhole article comprising:

a magnesium alloy core, and

a metallic layer covering the magnesium alloy core, the metallic layer being resistant to corrosion by a corrosive material,

wherein the corrodible downhole article prevents fluid flow when seated.

14. The method of claim 13, wherein seating comprises placing the article a downhole environment and applying pressure to the downhole environment.

15. The method of claim 14, further comprising removing the metallic layer of the corrodible downhole article, prior to seating, by injecting a slurry of a proppant into the downhole environment at a pressure greater than that of the downhole environment.

16. The method of claim 15, wherein the proppant slurry flows past the article and erodes the metallic layer to expose the magnesium alloy core.

17. The method of claim 14, further comprising unseating the corrodible downhole article by reducing the pressure applied to the downhole environment to a pressure below that of an ambient downhole pressure.

18. The method of claim 17, further comprising corroding the exposed magnesium alloy core in a corrosive material.

19. A method of removing a corrodible downhole article, the article comprising:

a magnesium alloy core, and

a metallic layer covering the magnesium alloy core, the metallic layer being resistant to corrosion by a corrosive material,

the method comprising eroding the metallic layer by physical abrasion, chemical etching, or a combination of physical abrasion and chemical etching, and

corroding the corrodible downhole article in the corrosive material after eroding.

20. An article for forming a downhole seal, comprising:

a magnesium alloy core, and

a metallic layer having a thickness of about 100 to about 500 micrometers and covering the magnesium alloy core, the metallic layer being formed of nickel, aluminum, or an alloy thereof, and resistant to corrosion by a corrosive material,

the article being a ball seat or frac plug.

21. A method of making an article for forming a downhole seal, comprising

plating, in the absence of water,

a metallic layer having a thickness of about 100 to about 500 micrometers and resistant to corrosion by a corrosive material, on

a surface of a magnesium alloy core,

the article being a ball seat or frac plug.