Downhole tool having low density slip inserts
A downhole tool, such as a fracture plug used during a fracture operation, installs in a downhole tubular, such as casing. The tool has a mandrel with a sealing element disposed thereon between uphole and downhole ends. Slip assemblies on the mandrel can be moved to engage the downhole tubular. The slip assemblies have inserts. The inserts have a body defining an internal cavity at least partially therein. The body is composed of a ceramic material having a first density of about 3 g/cc to about 6 g/cc. A volume of the insert can be about 0.4 cc to about 0.6 cc, and a mass of the insert can be about 1.2 g to about 3.6 g. In one example, the ceramic material is silicon nitride. The cavity can be filled with a low density filler material.
1. An insert used on a slip of a downhole tool to engage in a downhole tubular, the insert comprising:
a body defining an internal cavity at least partially therein, the body comprising a ceramic material having a first density of about 3 g/cc to about 6 g/cc,
wherein a volume of the insert is about 0.4 cc to about 0.6 cc, and
wherein a mass of the insert is about 1.2 g to about 3.6 g.
2. The insert of claim 1 , wherein the body comprises:
a first end configured to extend beyond a surface of the slip; and
a second end configured to install in the surface of the slip;
wherein at least one of the first and second ends defines an opening to the internal cavity.
3. The insert of claim 1 , wherein the ceramic material is selected from the group consisting of silicon nitride, alumina, aluminum oxide density, zirconia, and zirconium dioxide.
4. The insert of claim 1 , further comprising a filler disposed in the internal cavity, the filler comprising a second material having a second density at least less than about 3 g/cc.
5. The insert of claim 4 , wherein the second material is selected from the group consisting of aerogel, a dissolvable material, polyglycolide, magnesium, and aluminum.
6. An insert used on a slip of a downhole tool to engage in a downhole tubular, the insert comprising:
a body defining an internal cavity at least partially therein and having a first volume, the body comprising a first material having a first density; and
a filler disposed in the internal cavity and having a second volume, the filler comprising a second material having a second density less than the first density,
wherein a total volume of the insert combining the first and second volumes is about 0.4 cc to about 0.6 cc.
7. The insert of claim 6 , wherein the first volume of the body is about 0.4 cc to 0.5 cc, and wherein the second volume of the filler is about 0.1 cc to about 0.2 cc inverse to the first volume.
8. The insert of claim 6 , wherein the first density is about 6 g/cc to about 16 g/cc; and wherein the second density is about 0.1 g/cc to about 6 g/cc.
9. The insert of claim 8 , wherein the first material is selected from the group consisting of ceramic, zirconia, zirconium dioxide, a metallic material, a non-metallic material, a powdered metal, iron, brass, cermet, and tungsten carbide density.
10. The insert of claim 8 , wherein the second material is selected from the group consisting of aerogel, a dissolvable material, polyglycolide, magnesium, aluminum, silicon nitride, alumina, aluminum oxide, zirconia, and zirconium dioxide.
11. The insert of claim 8 , wherein a mass of the insert is about 3 g to about 9.2 g.
12. The insert of claim 6 ,
wherein the body defines a bore therethrough as the internal cavity; and
wherein:
the filler fills the bore from a first end of the body to a second end of the body; or
the filler fills the bore from the first end of the body to below the second end of the body and forms a base of the insert below the second end of the body.
13. The insert of claim 6 ,
wherein the body comprises a first end enclosing the internal cavity and has a second end being open to the internal cavity; and
wherein:
the filler fills the internal cavity from the first end to the second end; or
the second end defines a counterbore about the internal cavity and the filler fills the counterbore.
14. The insert of claim 6 , wherein the first material of the body comprises a silicon nitride with the first density of about 3 g/cc; and wherein second material of the filler has a second density at least less than 3 g/cc.
15. The insert of claim 14 , wherein the second material is selected from the group consisting of an aerogel, a dissolvable material, polyglycolide, magnesium, and aluminum.
16. An insert used on a slip of a downhole tool to engage in a downhole tubular, the insert comprising:
a body defining an internal cavity at least partially therein and having a first volume, the body comprising a first material having a first density; and
a filler disposed in the internal cavity and having a second volume, the filler comprising a second material having a second density less than the first density,
wherein the first material of the body comprises a silicon nitride with the first density of about 3 g/cc; and wherein second material of the filler has a second density at least less than 3 g/cc.
17. The insert of claim 10 , wherein a total volume of the insert combining the first and second volumes is about 0.4 cc to about 0.6 cc.
18. The insert of claim 16 , wherein the second material is selected from the group consisting of an aerogel, a dissolvable material, polyglycolide, magnesium, and aluminum.
19. The insert of claim 16 ,
wherein the body defines a bore therethrough as the internal cavity; and
wherein:
the filler fills the bore from a first end of the body to a second end of the body; or
the filler fills the bore from the first end of the body to below the second end of the body and forms a base of the insert below the second end of the body.
20. The insert of claim 16 ,
wherein the body comprises a first end enclosing the internal cavity and has a second end being open to the internal cavity; and
wherein:
the filler fills the internal cavity from the first end to the second end; or
the second end defines a counterbore about the internal cavity and the filler fills the counterbore.
21. A downhole apparatus for engaging in a downhole tubular, the apparatus comprising:
a mandrel having a first end and a second end;
a sealing element disposed on the mandrel between the first and second ends and compressible to engage the downhole tubular;
a first slip disposed toward the first end of the mandrel and being movable relative to the mandrel to engage the downhole tubular, the first slip having inserts; and
a second slip disposed toward the second end of the mandrel and being movable relative to the mandrel to engage the downhole tubular, the second slip having the inserts,
wherein one or more of the inserts comprise an insert according to claim 1 .
22. A downhole apparatus for engaging in a downhole tubular, the apparatus comprising:
a mandrel having a first end and a second end;
a sealing element disposed on the mandrel between the first and second ends and compressible to engage the downhole tubular;
a first slip disposed toward the first end of the mandrel and being movable relative to the mandrel to engage the downhole tubular, the first slip having inserts; and
a second slip disposed toward the second end of the mandrel and being movable relative to the mandrel to engage the downhole tubular, the second slip having the inserts,
wherein one or more of the inserts comprise an insert according to claim 6 .
23. A downhole apparatus for engaging in a downhole tubular, the apparatus comprising:
a mandrel having a first end and a second end;
a sealing element disposed on the mandrel between the first and second ends and compressible to engage the downhole tubular;
a first slip disposed toward the first end of the mandrel and being movable relative to the mandrel to engage the downhole tubular, the first slip having inserts; and
a second slip disposed toward the second end of the mandrel and being movable relative to the mandrel to engage the downhole tubular, the second slip having the inserts,
wherein one or more of the inserts comprise an insert according to claim 16 .