Safety joint:

If the tool cannot be disengaged from the fish, the safety joint permits easy disengagement of the string of pipe above the safety joint.

Thus, part of the safety joint and the tool attached to the fish remain in the hole and become part of the fish.

Terms Related to Safety joint

• Tool joint

  A heavy coupling element for drill pipe. It is made of special ahoy steel and has coarse, tapered threads and seating shoulders designed to sustain ...

• Spacing-out joint

  The joint of drill pipe that is used in hang-off operations so that no tool joint is opposite a set of preventer rams.

• Spinning chain

  A y-shaped chain used to spin up (tighten) one joint of drill pipe into another. One end of the chain is attached to the tongs, ...

• Space out

  The act of ensuring that a pipe ram preventer will not close on a drill pipe tool joint when the drill stem is stationary. A ...

• Downhole safety valve

  A downhole device that isolates wellbore pressure and fluids in the event of an emergency or catastrophic failure of surface equipment. The control systems associated with ...

• Safety factor of wire rope

  A measurement of load safety for wire rope obtained by using the following formula: safety factor - b/w where: b=nominal catalog breaking strength of the ...

• Flush-joint pipe

  Pipe in which the outside diameter of the joint is the same as the outside diameter of the tube. Pipe may also be internally flush-joint.