Degradable slip element
A slip element, including a substrate at least partially formed from a material degradable upon exposure to a fluid; and an outer surface disposed on the substrate. A method of removing a slip element including exposing a substrate of the slip element to a downhole fluid for degrading the substrate.
1. A slip element, comprising:
a substrate at least partially formed from a material degradable upon exposure to a fluid;
an outer surface disposed on the substrate, the outer surface having a hardness greater than a hardness of the substrate; and
a functionally graded layer is disposed between the outer surface and the substrate, the functional graded layer being distinct from and having a composition different than the outer surface.
2. The slip element of claim 1 , wherein the outer surface is formed at least partially from a different material than the substrate.
3. The slip element of claim 2 , wherein the outer surface comprises a composition of degradable and nondegradable materials with respect to the fluid, the composition having a slower rate of degradation than the substrate.
4. The slip element of claim 2 , wherein the outer surface consists solely of a nondegradable material and isolates the substrate from the fluid.
5. The slip element of claim 2 , wherein the outer surface has a hardness greater than that of the substrate.
6. The slip element of claim 2 , wherein the outer surface comprises at least one of a ceramic, a carbide, a nitride, a cermet, and a surface hardenable metal.
7. The slip element of claim 1 , wherein the substrate comprises a controlled electrolytic metallic material.
8. The slip element of claim 1 , further including at least one biting element disposed on or extending from the outer surface.
9. The slip element of claim 8 , wherein the biting element is provided on at least one tooth of the slip element.
10. The slip element of claim 1 , wherein the outer surface is formed by a coating.
11. A slip assembly comprising the slip element of claim 1 disposed in a molding.
12. The slip assembly of claim 11 , wherein the molding is nondegradable with respect to the fluid and isolates the substrate from the fluid.
13. The slip assembly of claim 12 , wherein at least one channel is formed extending through the molding to the substrate, the channel at least partially filled with the degradable material.
14. A method of removing a slip element comprising:
exposing a substrate of the slip element having an outer surface having a hardness greater than a hardness of the substrate and a functionally graded layer disposed between the substrate and the outer layer to a downhole fluid for degrading the substrate, the functionally graded layer being distinct from and having a composition different than the outer surface.
15. The method of claim 14 , wherein the slip element is disposed in a molding, the molding being nondegradable upon exposure to the downhole fluid for initially isolating the substrate from the downhole fluid.
16. The method of claim 15 , wherein exposing the substrate includes milling or drilling the molding.
17. The method of claim 14 , wherein the outer surface is nondegradable upon exposure to the downhole fluid.
18. The method of claim 14 , wherein the outer surface comprises a composition of degradable and nondegradable materials with respect to the fluid, and exposing the substrate includes first degrading the outer surface with the downhole fluid, wherein a degradation rate of the outer surface is slower than that of the substrate.