Downhole salvage tools are tools specially used to salvage fallen objects in underground environments such as oil wells and water wells. They usually have high strength and wear resistance, and can adapt to harsh conditions such as high pressure and high temperature in the well. The following are several common downhole salvage tools:

Slider slip salvage spear: It is an internal salvage tool specially used to salvage fallen objects with inner holes in the belt chain. It can also be used for inverted operation or in conjunction with other tools1.

Coupling spear: A tool specially used to salvage the top of the fish as a coupling1.

Telescopic salvage spear: It is a salvage tool taken out from the inner hole of the fish cavity. It can not only salvage free objects, but also salvage stuck objects1.

Spiral telescopic fishing bucket: It is a tool for salvaging from the outside of the pipe, which can salvage cylindrical fallen fish of different sizes, such as oil pipes, drill pipes, casing, etc.1.

Male cone: A tool specially used to make buckles and salvage from the inside of hole-shaped falling objects1.

Female cone: A tool specially used to make and salvage buckles from the outer wall of a tubular1.

Spiral outer hook: a downhole tool used to salvage fallen fishing lines, wire ropes, logging lines, etc. 1.

Local reverse circulation salvage basket: a tool used to salvage light debris at the bottom of the well 1.

Piston-type downhole salvage tool: includes a cylinder sleeve, a center tube and a working part. The center tube includes a tube body and a cone. The working part includes a piston sleeved between the cylinder sleeve and the center tube and a salvage mechanism connected to the lower end of the piston. The piston is constructed to be able to drive the salvage mechanism to slide downward in response to an increase in pressure, and the salvage mechanism is constructed to be able to expand radially in response to changes in the shape of the cone during the sliding process, so that the salvage mechanism can salvage the fallen fish out of the well 2.

The above are some common downhole salvage tools, which play an important role in the fields of oil extraction and groundwater development.