Products Category
QJZ MECHANICAL DRILLING JAR
2014-10-30 Browse:4273times
QJz mechanical drilling jar is fully mechanically operated and is an integrated unit that provides both up and down jarring operation. As part of the drill stem, it is used to free drill string components from sticking incidents and increase drilling efficiency by providing instantaneous jarring action without delay. The mechanical drilling jar relies on a trip and friction sleeve to activate jarring action. The jar is designed to trigger the jarring action when a sufficient amount of force (jar trip load) is applied to the jar in either up or down direction.
Working principle
● up Jarring
Up Jarring is achieved by pulling the drill string until it reaches the jar trip load. The jar trip load will cause the internal spring unit to deform, allowing the trip sleeve to engage the friction sleeve. When this happens, the mandrel is suddenly freed to release the jarring force. To reset the jar, remove the pull load by lowering the drill string.
● Down Jarring
There is another set of internal spring sleeve located at the top of the slips. Down Jarring is achieved by lowering(pushing) the drill string until it reaches the jar trip load. The jar trip load will cause the internal spring unit to deform, allowing the trip sleeve to engage the friction sleeve. When this happens, the mandrel is suddenly freed to release the jarring force. To reset the jar, remove the downward load by pulling the drill string.
Specifications - QJZ Mechanical Drilling Jar
