General Description
Bumper Jars are probably the most simple of all fishing tools, but also one of the most useful to a fishing tool supervisor.
Any properly made up fishing string will necessarily include a dependable Bumper Jar. The Fishing Bumper Jar will provide sustained bumping action, either upward or downward. It is rugged and dependable. Full circulation may be maintained through the tool at al times and in any position of stroke. The tool will transmit full torque in either direction and in any position of strike; open, close, or during stroke.
Use
The Fishing Bumper Jar is used in all types of fishing operations. It is usually made up in the string immediately above the fishing tool or safety joint (or both), enabling the operator to deliver forceful downward blows or upward blows at will. The Fishing Bumper Jar is used to break the “freeze” of engagement of fishing tools, to shear pins, to dislodge a stuck string, or to use as a “feed-off” tool in pipe cutting operations.
Fishing Bumper Subs are suited for all fishing operations; they will bump down, jar up, or help disengage a fish after retrieval. Their rugged simplicity makes them simple to operate and very easy to maintain. They are available in sizes to match all sizes of fishing strings, drill pipe, or tubing.
Construction
The Bumper Jar is a telescopic or slip jarring action. You determine exactly where the jar closes on the downward stroke and mark the pipe or Kelly at the top of the rotary. Then pick up until the jar is extended open, plus about 10,000 lbs. strain. At this time, drop the string as rapidly as possible, catching it will the mark three or four inches above the rotary. The stretch in the pipe will cause the jars to snap closed very rapidly. It is like slapping your hands together very rapidly.
The Bumper Jar is a good tool to have in the string to give you a neutral weight point. It also permits you to move the work string up and down to prevent sticking when in open hole. It can be used to run a predetermined amount of weight on the bottom when there is a need to. I am sure you can find other uses for them when the need arises.