BACKGROUND

Field

Embodiments of the present disclosure generally relate to a slip assembly for a downhole tool.

Description of the Related Art

Slips are used for various downhole tools, such as bridge plugs and packers. The slips can have inserts or buttons to grip the inner wall of a casing or tubular. Inserts for slips are typically made from cast or forged metal, which is then machined and heat-treated to the proper engineering specifications according to conventional practices.

Inserts for slips on metallic and non-metallic tools (e.g., packers, plugs, etc.) must be able to engage with the casing to stop the tools from moving during its operation. On non-metallic tools, such as composite plugs, the inserts can cause the non-metallic slips to fail when increased loads are applied. Of course, when the slip fails, it disengages from the casing. On non-metallic tools, the inserts also need to be easily milled up to assist in the removal of the tools from the wellbore.

A downhole tool, such as a bridge plug or a packer, can include a slip and a cone disposed on a mandrel. In operation, the slip and the cone are moved toward one another to cause the slip to move away from the mandrel and engage against a surrounding tubular or casing. Either the slip is pushed against the ramped surface of the cone, the cone is pushed under the slip, or both.

One particular type of downhole tool having slips is a composite fracture plug used in perforation and fracture operations. During the operations, the composite plugs need to be drilled up in as short of a period of time as possible and with no drill up issues. Conventional composite plugs use metallic wicker style slips, which are composed of cast iron. These metallic slips increase the metallic content of the plug and can cause issues during drill up in horizontal wells.

Due to the drawbacks of cast iron slips, some composite slips use inserts made of carbide. When the downhole tool having slips with carbide inserts are milled out of the casing, the inserts tend to collect in the casing and are hard to float back to the surface. In fact, in horizontal wells, the carbide inserts may collect at the heel of the horizontal section and cause potential problems for operations. Given that a well may have upwards of forty or fifty bridge plugs used during operations that are later milled out, a considerable number of carbide inserts may be left in the casing and difficult to remove from downhole.

There is a need, therefore, for a downhole tool having a slip assembly that is at least partially dissolvable.

SUMMARY

In one embodiment, a downhole tool for engaging a downhole tubular includes a slip assembly. The slip assembly may include a slip body; a slip insert disposed in the slip body, the slip insert comprising a dissolvable metal alloy; and a plurality of gripping elements coupled to the slip insert, the gripping element configured to engage the downhole tubular.

In another embodiment, a downhole tool for engaging a downhole tubular includes a cone having an inclined surface and a slip assembly configured to ride along the inclined surface. The slip assembly may include an injection molded slip body; a slip insert disposed in the slip body, the slip insert comprising a dissolvable metal alloy; and a plurality of gripping elements coupled to the slip insert, the gripping element configured to engage the downhole tubular.

