Miscellaneous Fishing Tools


This article describes the following fishing tools: Magnets,  Lead Impression Blocks, Rope Spears, Taper Taps and Die Collars.


The following guidelines should be used when using magnets:

  • The force of some magnets decreases with the age of the magnet. For this reason, when the magnet is not in use, the cover plate on the face shall be installed.
  • The pull of the magnet shall be checked prior to running it in the hole.
  • If a circulating magnet is not available, an open circulating sub or pin hole sub shall be placed above the magnet.

Lead Impression Blocks

The following guidelines should be used when using lead impression blocks:

  • A lead impression block may be used if additional information regarding the top of the fish is needed.
  • When the tool has reached a point just above the fish, circulation shall be started to clear the top of the fish before lowering the tool down to tag the top of the fish.
  • Weight shall be applied as required and the tool is brought back to the surface where the impression can be examined and interpreted.
  • A circulation sub or pin hole sub in the open position shall be installed above the lead impression block.

Rope Spears

The following guidelines should be used when using rope spears:

  • Rope spears may be used to fish broken wireline from the hole.
  • A stop ring shall always be run with a rope spear to prevent the spear from passing too far past the top of the wire rope.
  • After the tool has entered the wire rope it shall be rotated one or two turns only and overpull shall be taken until the line comes free or breaks at the weak point.

Taper Taps and Die Collar

The following guidelines should be used when using taper taps and die collars:

  • These tools are difficult to release once engaged and therefore a safety joint and jar shall be run with them. They shall generally only be run as a last resort.
  • External fishing tools and spears shall be run first.
  • Taper taps and die collars shall only be run by experienced personnel and extreme care shall be exercised when they are used to avoid sticking the entire string.
  • Taper taps have insufficient bore to allow passage of wireline tools such as back off charges or cutters, hence Company’s preference for external tools. A bumper safety joint must always be run with a die collar or taper tap.

Note: Bumper safety joint releases with left hand torque (coarse thread) only when in bumped position (normally locked). Tool ‘bumps’ when applying pre-set  compression.

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