Fishing tools tubular

There are basically three categories of fishing tools. These are (1) those used to define the geometry and orientations of the fish or junk in the borehole, (2) those used to recover tubular items (fish), and (3) those used to recover miscellaneous items (junk). 

There are two subcategories of tubular fishing tools those that can attach to the inside of the tubular fish and those that can attach to the outside of the tubular fish. 

Outside Fishing Tools. Outside fishing tools must pass over the outside of the fish before attaching themselves. The simplest of the outside fishing tools is the die collar, which is shown in Figure 4-357 with lipped guide. This is a short tubular that has case-hardened coarse threads cut in the inner surface of the tool. Such a tool is used to recover tubular items. 

There are items other than tubulars that must be fished from boreholes. These are drill bit parts, pieces of downhole tools left in the borehole and hand tools accidentally dropped in the borehole. Nearly all of these items cannot be drilled by a normal rock bit. Such items are called junk. 

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