Controlled application and monitoring of overpull

The D-Jar digital downhole adjustable jar is a surface-controlled, mechanical upstroke jar run as part of the LIVE Act digital slickline mechanical services. All jarring action is commanded and monitored directly by the operator. The D-Jar adjustable jar is closed and locked with real-time surface indication of tool status.

No loss of energy

Jarring energy is stored by applying overpull, which is monitored in real time via a downhole head tension sensor. When you are satisfied that the desired force is applied, you can command the D-Jar adjustable jar to fire, releasing the tool to stroke. The D-Jar adjustable jar is mechanical, so all the stored energy in the cable is applied to the jar—none is lost to hydraulics.

Repeatable, controlled jarring action

Jarring effect is measured directly downhole via an integrated accelerometer. The D-Jar adjustable jar can be reset and fired repeatedly with two unique features:

• jarring force that can be recalibrated in situ by applying the desired overpull tension with no need to pull to surface
• because the jar is mechanical, there is no loss in jarring efficiency after repeated firing.