Adjustable fishing jar
Auto set bi-directional jar
Downhole connector for use with drill string telemetering system
Downhole fishing jar mechanism
Fishing tool energizer and polymer energy storage element embodi
Mechanical directional drilling jar with swivel means
Mechanical drill string jar
Mechanical jarring devices for use in drilling
Mechanical well jar
Mechanical-hydraulic double-acting drilling jar
Multiple blow percussion drill assembly with rapid field mainten
Remotely adjustable fishing jar
Rotary jar
Tubular spring slip-joint and jar
Well jar incorporating elongate resilient vibration snubbers and