Methods of forming superelastic seals

• US 10,190,687 B2
• Filed: 12/27/2016
• Issued: 01/29/2019
• Est. Priority Date: 10/29/2014
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Roy, Sayantan, Sadana, Anil K.
• Primary Examiner(s): Foster, Nicholas L
• Application Number:
  US15/391,031
• Publication Number:
  US 20170108123A1
• Time in Patent Office: 763 Days
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22C 19/007 with a light metal (alkali metal Li, Na, K, Rb, Cs; earth alkali metal Be, Mg, Ca, Sr, Ba, Al Ga, Ge, Ti) or B, Si, Zr, Hf, Sc, Y, lanthanides, actinides, as the next major constituent
• CPC Class Codes: C22C 19/03 based on nickel
• CPC Class Codes: C22F 1/10 of nickel or cobalt or alloys based thereon
• CPC Class Codes: E21B 2200/01 Sealings characterised by their shape
• CPC Class Codes: E21B 33/12 Packers; Plugs used for cementing E21B33/134, E21B33/16
• CPC Class Codes: E21B 33/1212 including a metal-to-metal seal element
• CPC Class Codes: F16J 15/022 characterised by structure or material
• CPC Class Codes: F16J 15/0806 characterised by material or surface treatment
• CPC Class Codes: F16J 15/0887 the sealing effect being obtained by elastic deformation of the packing
• CPC Class Codes: F16J 15/3204 with at least one lip
• CPC Class Codes: F16J 15/328 Manufacturing methods specially adapted for elastic sealings moulding B29C
• CPC Class Codes: F16J 15/3284 characterised by their structure; Selection of materials

Abstract

A superelastic metal seal for use in a downhole tool, wherein the superelastic metal seal may be formed from a superelastic Ni—Ti alloy. The superelastic Ni—Ti alloy may be prestrained with a permanent strain. Superelasticity may be imparted to the superelastic Ni—Ti alloy through a thermal treatment process or through prestraining the superelastic Ni—Ti alloy. The superelastic Ni—Ti alloy may exhibit superelastic behavior. The superelastic Ni—Ti alloy may not exhibit shape memory behavior.

Claims

1. A method of forming a superelastic metal seal, comprising:

forming an Ni—

Ti alloy comprising from about 58 weight percent Ni to about 65 weight percent Ni and from about 35 weight percent Ti to about 42 weight percent Ti; and

treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior.

2. The method of claim 1, wherein treating the Ni—

Ti alloy comprises prestraining the Ni—

Ti alloy with a strain of at least approximately 2%.

3. The method of claim 1, wherein treating the Ni—

Ti alloy comprises hardening the Ni—

Ti alloy by rapidly cooling the Ni—

Ti alloy after hot working the Ni—

Ti alloy.

4. The method of claim 1, further comprising forming the superelastic metal seal into an O-ring shape, a C-ring shape, a D-seal shape, a T-seal shape, a V-seal shape, a X-seal shape, a flat seal shape, a lip seal shape, a cup seal shape, a back-up ring shape, a bonded seal shape, or a packing element shape.

5. The method of claim 1, wherein forming an Ni—

Ti alloy comprises forming an alloy comprising about 60 weight percent Ni and about 40 weight percent Ti.

6. The method of claim 1, wherein treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior comprises forming the superelastic Ni—

Ti alloy to exhibit superelastic behavior at least up to a compressive strain of about 10%.

7. The method of claim 1, wherein treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior comprises forming the superelastic Ni—

Ti alloy to exhibit a microcrystalline structure including a martensitic phase.

8. The method of claim 1, wherein treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior comprises forming the superelastic Ni—

Ti alloy to exhibit a microcrystalline structure including an austenitic phase.

9. The method of claim 1, wherein treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior comprises forming the superelastic Ni—

Ti alloy to exhibit a microcrystalline structure including a martensitic phase and an austenitic phase.

10. The method of claim 1, wherein treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior comprises forming the superelastic Ni—

Ti alloy to have a Rockwell hardness of about HRC 35-40, about HRC 40-45, about HRC 45-56, about HRC 56-62, or greater than about HRC 62.

11. The method of claim 1, wherein treating the Ni—

Ti alloy to form a superelastic Ni—

Ti alloy that is not capable of shape memory behavior comprises forming the superelastic Ni—

Ti alloy to substantially resist degradation in the presence of one or more of KCl, NaCl, CaCl₂, CaBr₂, and ZnBr₂.

12. A method of forming a superelastic metal seal, comprising:

forming an alloy comprising from about 58 weight percent Ni to about 65 weight percent Ni and from about 35 weight percent Ti to about 65 weight percent Ti; and

subjecting the alloy to one or more of a thermal treatment process and a physical stress application process to form a superelastic alloy that is not capable of shape memory behavior.

13. The method of claim 12, wherein forming an alloy comprises forming the alloy through one or more of one or more of a powder sinter process, a powder metallurgy process, a vacuum melting process, an electron beam melting process, a vacuum arc melting process, a high frequency vacuum melting process, a vacuum induction melting process, and a plasma melting process.

14. The method of claim 12, wherein subjecting the alloy to one or more of a thermal treatment process and a physical stress application process comprises:

isostatically pressing and hot rolling the alloy to form a pressed, heated alloy; and

quenching the pressed, heated alloy in oil or gas to form the superelastic alloy.

15. The method of claim 12, wherein subjecting the alloy to one or more of a thermal treatment process and a physical stress application process comprises:

isostatically pressing and hot rolling the alloy to form a pressed, heated alloy; and

cooling the heated alloy to form a pressed, cooled alloy; and

applying one or more of tensile stress and compressive stress to the pressed, cooled alloy to permanently strain the pressed, cooled alloy and form the superelastic alloy.

16. The method of claim 12, further comprising subjecting the superelastic alloy to one or more of a machining process, a grinding process, a cutting process, and a molding process to form a seal structure.

17. A method of forming a superelastic metal seal, comprising:

forming an Ni—

Ti alloy comprising from about 58 weight percent Ni to about 65 weight percent Ni and from about 35 weight percent Ti to about 65 weight percent Ti;

forming a seal structure from the Ni—

Ti alloy; and

subjecting the seal structure to one or more of a thermal treatment process and a physical stress application process to convert the Ni—

Ti alloy thereof into a superelastic Ni—

Ti alloy that is not capable of shape memory behavior.

18. The method of claim 17, wherein forming a seal structure from the Ni—

Ti alloy comprises processing the Ni—

Ti alloy to form an O-ring, a C-ring, a D-seal, a T-seal, a V-seal, an X-seal, a flat seal, a lip seal, a cup seal, a back-up ring, a bonded seal, or a packing element.

19. The method of claim 17, wherein subjecting the seal structure to one or more of a thermal treatment process and a physical stress application process comprises subjecting the Ni—

Ti alloy to a strain within a range of about 2% to about 15%.

20. The method of claim 17, wherein subjecting the seal structure to one or more of a thermal treatment process and a physical stress application process imparting the seal structure with a permanent strain of at least about 0.5%.