Mechanical Drilling Jar Types, Mechanism & components
Mechanical drilling jars is different from Hydraulic Drilling Jars Operation & Mechanism as it have a preset load setting that must be applied before the jar will fire. They are sensitive to load only and not time. To increase or decrease the jarring tension, the jars must be tripped to surface, in other words the string must become unstuck. You might be interested in Drilling Jar Placement & Calculations article.
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