Superelastic nickel-titanium alloy downhole seals, wellbore tools including such seals, and related methods
View Patent ↗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.
1. A superelastic metal seal, comprising a superelastic Ni—Ti alloy, the superelastic Ni—Ti alloy including, by weight percent, about 65% to about 58% nickel (Ni) and about 35% to about 42% titanium (Ti), and wherein the superelastic Ni—Ti alloy is not capable of shape memory behavior.
2. The superelastic metal seal of claim 1 , wherein the superelastic Ni—Ti alloy is prestrained with at least approximately a 2% permanent strain.
3. The superelastic metal seal of claim 1 , wherein the superelastic Ni—Ti alloy comprises, by weight percent, about 60% nickel (Ni) and about 40% titanium (Ti).
4. The superelastic metal seal of claim 1 , wherein the superelastic Ni—Ti alloy exhibits superelastic behavior at least up to a compressive strain of about 10%.
5. The superelastic metal seal of claim 4 , wherein the superelastic Ni—Ti alloy exhibits superelastic behavior at least up to a compressive strain of about 15%.
6. The superelastic metal seal of claim 1 , wherein the superelastic Ni—Ti alloy exhibits superelastic behavior within a temperature range of from about 120° C. to about 205° C.
7. The superelastic metal seal of claim 6 , wherein the superelastic Ni—Ti alloy exhibits superelastic behavior in a temperature range of from about 20° C. to about 400° C.
8. The superelastic metal seal of claim 1 , wherein the superelastic metal seal is configured for use in a downhole hole tool assembly and is selected from the group consisting of O-rings, C-rings, D-seals, T-seals, V-seals, X-seals, flat seals, lip seals, cup seals, backup rings, bonded seals, and packing elements.
9. A downhole tool, comprising:
a component; and
a superelastic metal seal disposed adjacent the component, the superelastic metal seal comprising a superelastic Ni—Ti alloy including, by weight percent, about 65% to about 58% nickel (Ni) and about 35% to about 42% titanium (Ti), and wherein the superelastic Ni—Ti alloy exhibits superelastic behavior within a temperature range of from about 120° C. to about 205° C. and is not capable of shape memory behavior.
10. The downhole tool of claim 9 , wherein the superelastic Ni—Ti alloy exhibits superelastic behavior within a temperature range of from about 20° C. to about 400° C.
11. The downhole tool of claim 9 , wherein the superelastic Ni—Ti alloy comprises, by weight percent, about 60% nickel (Ni) and about 40% titanium (Ti).
12. The downhole tool of claim 9 , wherein the superelastic Ni—Ti alloy is plastically prestrained.
13. The downhole tool of claim 10 , wherein the superelastic Ni—Ti alloy is plastically prestrained with at least approximately a 2% permanent strain.
14. The downhole tool of claim 9 , wherein the superelastic Ni—Ti alloy exhibits superelastic behavior at least up to a compressive strain of about 10%.