Project Description

Hydraulic/Mechanical Drilling Jar

The Wenzel Downhole Tools Hydraulic/Mechanical Drilling Jar (HMJ) 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.  The HMJ 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 HMJ is normally operated in the latched position to reduce unexpected jarring while drilling and eliminate movement between jar components, increasing service life.
  • The HMJ 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 jar 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 HMJ can be run in tension or in compression within the preset latch settings.

Mechanical Tripping Mechanism

The normal setting for the mechanical latch is the down jarring load being 50% of the up jarring load. This tripping ratio, along with the tripping load, can easily be altered to suit customer requirements.

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. See product flyer PDF for technical specifications on the maximum pull during delay.
  • After impact, apply a downward 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 HMJ 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
(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)
3.12 13.9 1.00 154 500 8 200 25 000 11 000 42 000 5.0 6.5
3.50 14.9 1.25 211 500 10 300 35 000 15 000 50 000 5.0 7.0
3.75 15.1 1.19 214 000 11 300 35 000 15 000 65 000 5.0 7.0
4.75 17.0 2.25 391 000 20 000 55 000 30 000 85 000 5.0 6.0
5.25 17.9 2.25 554 100 31 000 55 000 30 000 120 000 5.0 6.0
6.25 18.0 2.25 777 000 48 500 90 000 40 000 160 000 5.0 6.0
6.50 18.0 2.25 777 000 52 400 90 000 40 000 160 000 5.0 6.0
6.62 17.9 2.75 722 500 53 800 90 000 40 000 170 000 5.0 6.0
6.75 17.9 2.75 907 500 48 800 95 000 42 000 190 000 5.0 6.0
8.00 18.2 2.81 949 000 98 000 100 000 45 000 240 000 5.5 6.0
9.00 19.1 3.00 1 221 000 162 500 110 000 50 000 240 000 5.5 6.0
9.50 19.2 3.00 1 658 500 178 400 110 000 50 000 240 000 5.5 6.0

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

Metric

Nominal OD
(mm)		 Length
(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)
79 4.2 25 68 700 11 100 11 100 4 900 18 700 130 170
89 4.5 32 94 100 14 000 15 600 6 700 22 200 130 180
95 4.6 30 95 200 15 300 15 600 6 700 28 900 130 180
121 5.2 57 173 900 27 100 24 500 13 300 37 800 130 150
133 5.5 57 246 500 42 000 24 500 13 300 53 400 130 150
159 5.5 57 345 600 65 800 40 000 17 800 71 200 130 150
165 5.5 57 345 600 71 000 40 000 17 800 71 200 130 150
168 5.5 70 321 400 72 900 40 000 17 800 75 600 130 150
171 5.5 70 403 700 66 200 42 300 18 700 84 500 130 150
203 5.5 71 422 100 132 900 44 500 20 000 106 800 140 150
229 5.8 76 543 100 220 300 48 900 22 200 106 800 140 150
241 5.9 76 737 700 241 900 48 900 22 200 106 800 140 150

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