Project Description

Ultimate Hydraulic / Mechanical Drilling Jar

The Ultimate Hydraulic/Mechanical Drilling Jar (UHMJ) is a double acting jar, designed to deliver hydraulic delay when jarring in the up direction, and mechanical release when jarring in the down direction.

Using proprietary new technology, Wenzel Downhole Tools has been able to dramatically increase the allowable overpull force.  The UHMJ incorporates a latch mechanism to keep the jar locked in the neutral position and eliminate unexpected jarring while tripping or racking on the derrick.

  • The UHMJ is normally operated in the latched position to reduce unexpected jarring while drilling and eliminate movement between jar components, increasing service life.
  • The UHMJ operates with a simple up and down motion and is not affected by torque.
  • The spline drive and latch mechanism are enclosed in a single, sealed oil chamber without ports to the annulus.  Such ports on other jars may fill with cuttings and restrict the down jar stroke.
  • The hydraulic delay mechanism is located in a separate chamber to prevent contamination and increase reliability.
  • With the latch mechanism in the latched position, the inner mandrel and outer housing act integrally, virtually eliminating seal and inner tool wear during normal drilling conditions.  There is no need to extend or open the UHMJ before running in the hole.
  • Standard seals in the tool are effective to 250°F (120°C). The jar 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
  • The UHMJ can be run in tension or in compression within the preset latch settings.

Jarring Up

  • Jarring up is achieved by applying sufficient overpull to overcome the latch setting, which initiates the hydraulic time delay.  During the time delay, the overpull at surface can be adjusted to vary the impact force.
  • After impact, apply a down force sufficient to close jar and re-engage latch, then repeat the jarring cycle as required.

Jarring Down

  • Jarring down is achieved by applying sufficient downward force to overcome the latch setting and pump open force.  At that point, the UHMJ will release and jar downward. After impact, pick up the work string to re-engage the mechanical latch then repeat the jarring cycle as required.

Imperial

Nominal OD
(inch)		 Length
Space
(ft)		 Thru Bore
(inch)		 Tensile Yield
(lbs)		 Torsional Limit
(ft-lbs)		 Nominal Up Latch Setting
(lbs)		 Nominal Down Latch Setting
(lbs)		 Max Pull During Delay
(lbs)		 Free Stroke Up
(inch)		 Free Stroke Down
(inch)
4.13 18.9 2.00 280 000 15 000 45 000 25 000 110 000 5.0 6.0
4.75 19.6 2.25 391 000 20 000 55 000 30 000 132 000 5.0 6.0
5.25 19.6 2.25 391 000 31 500 55 000 30 000 132 000 5.0 6.0
6.25 20.5 2.25 777 000 48 500 90 000 40 000 250 000 5.0 6.0
6.50 20.5 2.25 777 000 52 400 90 000 40 000 250 000 5.0 6.0
6.62 20.6 2.75 722 500 53 800 90 000 40 000 250 000 5.0 6.0
6.75 20.5 2.75 907 500 48 800 95 000 42 000 270 000 5.0 6.0
8.00 20.7 2.81 949 000 98 000 100 000 45 000  400 000 5.5 6.0
10.00 21.9 3.00 1 658 500 182 200 110 000 50 000 580 000 5.5 6.0

Specifications are based on as new condition and are subject to change without notice.

Metric

Nominal OD
(mm)		 Length Space
(m)		 Thru Bore
(mm)		 Tensile Yield
(daN)		 Torsional Limit
(Nm)		 Nominal Up Latch Setting
(daN)		 Nominal Down Latch Setting
(daN)		 Max Pull During Delay
(daN)		 Free Stroke Up
(mm)		 Free Stroke Down
(mm)
105 5.8 51 124 500 20 300 20 000 11 100 48 900 130 150
121 6.0 57 173 900 27 100 24 500 13 300 58 700 130 150
133 6.0 57 173 900 42 700 24 500 13 300 58 700 130 150
159 6.3 57 345 600 65 800 40 000 17 800 111 200 130 150
165 6.3 57 345 600 71 000 40 000 17 800 111 200 130 150
168 6.3 70 321 400 72 900 40 000 17 800 111 200 130 150
171 6.2 70 403 700 66 200 42 300 18 700 120 100 130 150
203 6.3 71 422 100 132 900 44 500 20 000 177 900 140 150
254 6.7 76 737 700 247 000 48 900 22 200 258 000 140 150

Specifications are based on as new condition and are subject to change without notice.