The Jar Intensifier is perhaps one of the most outstanding devices designed to help fishermen successfully complete difficult fishing jobs in the oil and gas field. The tool is designed to become a fishing string component and work in conjunction with a hydraulic jar to ensure that the jarring blows are concentrated at the stuck pipe point.
The restraining mechanism in a Hydraulic Drilling Jar (an expansion joint with a limited longitudinal stroke) permits the buildup of extreme energy in the drill pipe and the ability to suddenly release the energy to drive a mass of weight upward to strike a heavy jarring blow. The mass of weight is composed of those drill collars that are installed above the Jar. The energy built up in the stretched drill pipe is often partially dissipated by hole friction, crooked holes, etc. If the tremendous energy stored in the drill pipe can be concentrated at a point close to where the fish is stuck and released forcefully at that point, the net result of the jarring effort is greatly increased.
Therefore, the Jar Intensifier is installed immediately above the drill collars. The design of an effective tool of this type is possible because of the development of a good compressible fluid and the unique and extremely effective Seal Ring Assembly similar to that used in the Hydraulic Jar.
The Intensifier is essential in shallow holes when the pipe is insufficient to achieve the necessary stretch to strike a blow.