Hydraulic-Mechanical Drilling Jar

Working Principle

Up Jarring

Lowering Drill String to make drilling jar closed completely (in locking position), elevating drill string by the order of small tonnage to larger tonnage, which make spring and hydraulic cylinder delay, when mandrel move to a position and become release resistance, the spring force stored in drill string will transfer to up forward energy and up jarring. Repeating the above several times can force tool to produce continues up jarring.

Down Jarring

Move up and down the drill string to make drilling jar closed completely (in locking position), lowering drill string to make spring compressed and stored energy. When pressure of jar is larger than the desired lower unlocking force, grapple will slide out from mandrel to release the locking and make down jarring. Repeating the above several times can force tool to produce continues down jarring.

ZSJ/ZXJ Hydraulic & Mechanical Two-piece Drilling Jar

The drilling jar connecting with drill tool and working with drill strings is a downhole stuck freeing tool in drilling operation. When drill tool is happened to be stuck in downhole, the stuck drill tool can be released by in time starting the drilling jar to provide continuous up jarring or down jarring. It is a desire tool for directional well, complicated well and deep well.

The drilling jar is consisting of ZSJ type drilling up jar and ZXJ type drilling down jar, both can be used mutually or operated separately. The up jarring section takes use of hydraulic mechanism; the jarring force can be adjusted according to up elevating load but can not exceed the max. load for tool load rated. The down jarring section takes use of mechanical friction mechanism; the jarring force is well preadjusted by adjusting device before put into down-hole. No re-adjustment can be allowed after jar is put intodown-hole.