Downhole tools having features for reducing balling, and methods of forming such tools
View Patent ↗Downhole tools are provided with a topographical pattern, and anti-balling material is provided over the topographical pattern. The topographical pattern may be defined by at least one of a plurality of recesses extending into a surface of a body of the tool and a plurality of protrusions protruding from the surface. Downhole tools include an insert disposed within a recess in a body, and the insert comprises an anti-balling material having a composition selected to reduce accumulation of formation cuttings on the tools when the tools are used to form or service a wellbore. Downhole tools include anti-balling material disposed over a porous mass provided over the surfaces of the tools. Methods of forming downhole tools include providing anti-balling material over features on and/or in a surface of a body of a tool. Methods of repairing downhole tools include removing an insert therefrom and disposing a replacement insert therein.
1. An anti-balling insert for use on a downhole tool having a plurality of blades, the anti-balling insert comprising:
an insert body having a size and shape configured to be disposed at least partially in a recess in a bottom surface of a fluid course defined by two adjacent blades of the plurality of blades of the downhole tool, wherein the bottom surface of the fluid course is between a leading surface of a first blade and a trailing surface of a second, adjacent blade; and
an anti-balling material disposed on an outer surface of the insert body, the anti-balling material having a composition for reducing accumulation thereon of formation cuttings removed from a subterranean formation by the downhole tool.
2. The anti-balling insert of claim 1 , wherein the anti-balling material is hydrophobic.
3. The anti-balling insert of claim 1 , wherein the anti-balling material has a coefficient of friction from about 0.05 to about 0.20.
4. The anti-balling insert of claim 1 , wherein the anti-balling material comprises at least one of a polymer, a metal, a metal alloy, a ceramic, diamond, diamond-like carbon, graphite, molybdenum disulfide, boron nitride, aluminum, and silicone.
5. The anti-balling insert of claim 4 , wherein the anti-balling material comprises a polymer.
6. The anti-balling insert of claim 1 , wherein the material of the insert body is softer than the anti-balling material.
7. The anti-balling insert of claim 1 , wherein the anti-balling material has a thickness in a range extending from about 1 micron to about 50 microns thick.
8. A downhole tool, comprising:
a bit body having a plurality of blades,
at least one anti-balling insert comprising:
an insert body having a size and shape configured to be disposed at least partially in a recess in a bottom surface of a fluid course defined by two adjacent blades of the plurality of blades of the downhole tool, wherein the bottom surface of the fluid course is between a leading surface of a first blade and a trailing surface of a second, adjacent blade; and
an anti-balling material disposed on an outer surface of the insert body, the anti-balling material having a composition for reducing accumulation thereon of formation cuttings removed from a subterranean formation by the downhole tool.
9. The downhole tool of claim 8 , wherein the anti-balling material is hydrophobic.
10. The downhole tool of claim 8 , wherein the anti-balling material has a coefficient of friction from about 0.05 to about 0.20.
11. The downhole tool of claim 8 , wherein the anti-balling material comprises at least one of a polymer, a metal, a metal alloy, a ceramic, diamond, diamond-like carbon, graphite, molybdenum disulfide, boron nitride, aluminum, and silicone.
12. The downhole tool of claim 8 , wherein the at least one anti-balling insert comprises at least one exposed sharp edge.
13. The downhole tool of claim 8 , further comprising an adhesive material between the bit body and the at least one anti-balling insert.