Fish

An object that is left in the wellbore during drilling or workover operations and that must be recovered before work can proceed. It can be anything from a piece of scrap metal to a part of the drill stem.

v.

1) to recover from a well any equipment left there during drilling operations, such as a lost bit or drill collar or part of the drill string.

2) to remove from an older well certain pieces of equipment, such as packers, liners, or screen liner, to allow reconditioning of the well.