Retrieval & Fishing Tools

Retrieval and fishing tools are used to connect with an item, or fish, that was either lost or intentionally placed in the well. There are two main types of fishing necks used: the internal GS profile and the external JDC profile.

Fishing tools are designed to engage with items that were not originally designed to be engaged i.e., items without an engagement profile. In many cases, the items are lost or broken off pieces of tool strings or coiled tubing. These items have to be engaged either internally or externally. A bar or rod sticking up would call for an overshot tool; a pipe or other large bore could be caught with a spear. Both the overshot and the spear cut into the metal of the fish to engage with it.

All retrieval tools, and many spears and overshots, are releasable to provide the option to come off the fish in case it cannot be moved. Common is the mechanical release function and the hydraulic release function. Most operators prefer the hydraulic release choice. However in gas wells, which do not support a fluid column, or in case the introduction of water to the formation has to be minimized, the mechanic release tool has the advantage. Nonreleasable tools must be used with a disconnect above, and the risk of having to leave them in the well has to be accepted.