The Wenzel HMDA is a double-acting hydraulic jar designed to deliver a hydraulic delay when jarring in both the up and down directions. What makes the HMDA different is the mechanical latch that keeps the jar locked in the neutral position. This latch eliminates unexpected jarring during operation and handling—and keeps people safe.

Simple operation

Like our HJDA, the HMDA jar incorporates a Visco Jet metering device that ensures consistent delay times over a full range of operating temperatures, up to 250°F (120ºC) with standard seals or 450ºF (230ºC) with the addition of heat-resistant seals. Delayed jar firing allows the driller to control loads.

The HMDA can be run in tension or in compression within the preset latch setting and operates via a simple up and down motion that is unaffected by right- or left-hand torque.

Built to last

The HMDA, like all other Wenzel jars, is designed without any housing ports to the annulus. Such ports can restrict jar stroke, impact strength and seal integrity. The spline drive and latch mechanism are enclosed in a single oil chamber and the double-acting hydraulic valves in a second oil chamber. Minimizing the number of oil chambers reduces the seals required, increasing jar reliability.

Features

• Hydraulically activated in both directions with impact force controlled by operator
  • Impact force can be adjusted by configuring internal metering device
  • Metering device ensures consistent delay times over a full range of operating temperatures
• While drilling, mechanical latch eliminates unexpected jarring and movement between jar components, which extends service life
• Spline drive and latch mechanism enclosed inside oil chamber without ports to annulus
  • Such ports on competitor jars can restrict jar stroke, impact and seal integrity
• Operates via simple up and down motion, unaffected by right- or left-hand torque
• Can be run in tension or compression within the preset latch setting
• Can be configured with single-direction hydraulic delay
• Standard seals effective to 250°F (120°C); can be dressed with seals effective to 450°F (230°C) for hot hole environments
• External sealing surfaces are tungsten carbide-coated to enhance wear and corrosion resistance

The Wenzel HMDA can be easily converted to a Double-Acting Hydraulic Jar (HJDA) or a Hydraulic Mechanical Single-Acting jar (HMSA). The HMSA conversion is done with the simple removal of the down-firing hydraulic valve. The convertibility of our HMDA also gives you flexibility to move these assets into any region for any application.