Hydraulic Jar

Hydraulic Jar


The Hydraulic Jars allow jarring of the test string to aid in the freeing of downhole tools. The jar provides a temporary resistance that allows the drill pipe to be stretched. When the resistance is release, the drill pipe contracts to deliver the impact and freeing force.


Freeing stuck section of the drill string in cased hole or open hole testing operations.


Pulling on the drill string at surface will allow for tubing stretch and mandrel movement upward as hydraulic fluid is restricted against the resistance valve and the lower jar body and lower portion of the string remain fixed. Once the travel in the hydraulic chamber is used up, the jar body will fire rapidly upwards to free the stuck zone below. The HJ is easily reset by putting weight on the drill string and filling up the hydraulic chamber for repeat jarring.


O.D. 5" 3.125"
I.D. 1.25” 1.125”
Length 2.03 m (6.66') 2.03 m (6.66')
Mandrell Torque 2,500 ft lb 2,500 ft lb
Tensile Strength 290,000 lbs 120,000 lbs
Temperature Rating -40°F to 250°F -40°F to 250°F
Pressure Rating 5,000 lbs 5,000 lbs
Time to Fire 2 to 5 minutes 2 to 5 minutes
Low Pull 10,000 lbs 10,000 lbs
Time to Fire 30-60 seconds 30-60 seconds
High Pull 50,000 lb 38,000 lb
Connections 3 ½ IF 2 3/8 IF
Service H2S + CO2 H2S + CO2
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