Water Well Fishing Tools
Hopefully, you will never need to fish inside your water well. But if you do, specialized fishing tools can grip and retrieve lost pipes, bits, broken parts, fittings, filings or debris from the depths of your water well. Fishing tools are only part of the retrieval equation. Water well fishing tools often require the use of a boom truck to lower them into the well and raise them out.
The Anatomy of a Well
Water wells consist of three major parts: an outside casing, a steel water pipe inside the casing, and a pump, which in most instances attaches to the bottom of the pipe. It may be tempting to pull broken pipe up using the electrical wiring attached to the pump, but it will not support the weight of the pipe and debris and is not recommended. Above-ground pumps also incur problems with lost or broken pipes, fittings or debris below ground and require the use of "fishing" tools to retrieve them. Problems with lost parts or pipes may occur during the drilling of the well or when sections of the pipe or fittings separate from each other or break. Three types of fishing tools are typically used to retrieve lost or broken items; taper taps, external, or "overshot," tools and magnets.
The taper tap, or spear, is an internal catch tool that is typically the first tool used to retrieve broken pipe from water wells or drill bits which attach to pipes. A taper tap or spear might look like a tapered cone with threads or it might have an appearance much like an old-fashioned auger with twisted spirals. The spear attaches to one end of a pipe and, when lowered into the casing, enters the end of the pipe or bit. The spear works like any other screw or bolt. When twisted, the spear bores, or threads, into the lost pipe or bit with the tapered threads, connecting the spear to the pipe or pump below it. The pipe can then be lifted out of the well, along with the pump.
Overshot tools are external catch devices that do the opposite of taper taps, connecting to threads around the outside diameter of the pipe to be retrieved. Use an overshot tool to retrieve lost pipes and drill bits when it's not possible to use a spear. The overshot tool attaches to the bottom of a pipe with a diameter similar to that of the lost pipe, and is lowered into the casing. The overshot grips the outside diameter of the lost pipe, securing the assembly to the pipe so that it can be raised out of the well.
Some objects can only be removed from a water well using magnetic fishing tools. Use magnets when problems occur with broken fittings, debris, junk, or metal filings or cuttings from broken or stripped pipes. Water well magnets work via electronic signals to retrieve smaller parts that aren't accessible to overshots or taper taps. The concept is basic: Lower the magnet into the hole, charge or activate the magnet, and lift lost parts or metallic debris to the surface.
Use junk catchers or grapple baskets to retrieve lost parts, fittings or debris that do not respond to magnetic attraction. The junk catcher attaches to a pipe of similar diameter and is lowered into the existing casing. It has tapered tongs or fingers that surround or enclose small objects. When fluid is pumped into the pipe, debris or lost items flush upward into a basket or catcher where they remain contained. The junk catcher is then lifted out of the pipe, along with the debris or broken parts.