Lubricated fishing bumper sub is one of the jars which produce jarring force by means of the energy caused by heavy weight objects when moving down, its inner chamber is full of hydraulic oil so as to ensure a longer service life. The tool is suitable for deep hole and middle deep hole operation. With some advantages: Can produce strong one way down jarring force, maximum jarring force, continuous down jarring force. Medium jarring force; continuous up jar, low-grade jarring force; can release fishing tool; can act as constant pressure drill tool, simply structure, easy operation, all these make it widely used jarring tool....

The surface jar is an effective tool for resolving the problem of drill tool stuck in down hole. It is connected with the surface section of drill string, the device to adjust the tonnage shall protrude from the rotary disc face, the violent down jarring to the stuck catch can be clearly seen when the surface jar makes jarring operation. The jarring strength for the tool can be easily adjusted and it is an easy operated, unique designed tool which can make continuous down jarring. The surface jar, which not only can bear heavy load and strong torque but also owns a good sealing property and can withstand the mud circulation with high pump pressure, has proven to be a safe, successfully effective releasing tool through many years using....