The Wenzel HJDA is a purely hydraulic bidirectional drilling jar that allows the operator to apply variable impact in both the up and down directions—unaffected by left- or right-hand torque.

Variable, operator-controlled impact is achieved thanks to a pair of hydraulic metering valves that feature high level flow restriction with large passage. The metering device (Visco Jet) ensures consistent delay times over a full range of operating temperatures and delay can be changed by swapping jets. These high-performance valves have been used successfully in the aerospace industry, where precision and reliability are paramount.

Because of the HJDA’s latch-free design, the range of jar placement options increases significantly. The HJDA can be used in tension or compression and is an excellent option when available force is not sufficient to jar down with conventional HMJ drilling jars.

Simpler, smaller, cost effective

The minimalist design of our HJDA makes it the shortest drilling jar on the market. Fewer oil seal chambers and parts keep costs down and maintenance simple. By shortening the length of the HJDA, longer flex collars can be used to reduce bending stress across the jar.

To further increase its durability, we coat all external sealing surfaces with wear and corrosion resistant tungsten carbide.

Feature overview

• Purely hydraulically controlled with impact force controlled by the operator
  • Impact force controlled by metering device that ensures consistent delay times over the full range of operating temperatures
  • Operates via simple up and down motion
• Jars in both the up and down directions
• Unaffected by right- or left-hand torque
• Shortest drilling jar on the market
• Minimal oil seal chambers and moving parts, which keeps costs down and maintenance simple
• Standard seals in the tool are effective to 250°F (120°C); can be dressed with seals effective to 400°F (200°C) for hot hole environments, and 450°F (230°C) for extreme temperature environments
• External sealing surfaces are tungsten carbide-coated to enhance wear and corrosion resistance

Expand your options with convertible jars

Keep both hydraulic and mechanical jar options on hand with a single asset and minimal inventory thanks to Wenzel’s convertible jar system. The HJDA can be easily converted to both a Hydraulic Mechanical Double-Acting drilling jar (HMDA) or a Hydraulic Mechanical Single-Acting jar (HMSA). The convertibility of our HJDA gives you flexibility to move these assets into any region for any application.

Additionally, the Wenzel HJDA is available in our exclusive ULTIMATE configuration, which gives operators the highest overpull capacity on the market.