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 built-in mechanical latch keeps the jar locked in a neutral position, which prevents stroking of the jar downhole and unintentional firing of the jar while drilling or tripping. When latched, the mandrel and housing act integrally, eliminating seal and inner-tool wear. The latch eliminates the need for a safety collar and special handling/precautions on the rig floor.
The hydraulic valve provides delay when jarring up, allowing drillers to vary overpull and control impact force. The valve resides in its own oil seal chamber for increased reliability, and a robust metering device controls delay times across operating temperatures.
Down strokes use the mechanical part of the jar, while upward strokes use the hydraulic part with hydraulic delay. The mechanical latch actuation force can be adjusted and set during the jar assembly upon customer request.
| SDT-HMJ475 | SDT-HMJ675 | SDT-HMJ800 | SDT-HMJ950 | |
| Nominal OD (A), in | 4.88 | 6.73 | 8 | 9.5 |
| Thru Bore (B), in | 2.16 | 2.75 | 2.75 | 3 |
| Free stroke Up, in | 9 | 9 | 9 | 9 |
| Free stroke Down, in | 5.9 | 5.9 | 5.9 | 5.9 |
| Length in fixed position (C), ft | 22.14 | 22.15 | 22.97 | 22.97 |
| Hydraulic delay time, sec | 30 – 150 | 30 – 150 | 30 – 150 | 30 – 150 |
| Nominal Up latch setting, lbs | 55 000 | 130 000 | 154 300 | 165 000 |
| Nominal Down latch setting, lbs | 35 900 | 70 500 | 99 200 | 108 000 |
| Pump Open Area, in.sq. | 11.78 | 23.7 | 30.69 | 41.2 |
| Maximum pull during hydraulic delay, lbs | 76 200 | 189 600 | 242 500 | 242 500 |
| Tensile yield, lbs | 391 000 | 705 500 | 804 500 | 1 197 000 |
| Torsional limit, ft-lbs | 13 276 | 36 100 | 61 900 | 125 400 |
| Connecting threads | NC38 | NC50 | 6 5/8 Reg | 7 5/8 Reg |
| Make up torque, ft-lbs | 8 851 – 10 325 | 28 750 – 33 200 | 47 900 – 51 500 | 59 000 – 66 400 |
| Maximum operating temperature, °F | 302 °F | 302 | 302 | 302 |
| Weight, lb | 749 | 1 926 | 2 866 | 4 079 |
* Actual values are supplied in tool test report
** Tool should be sent for maintenance every 250 hours when used in environment with chloride content higher than 50,000 mg/l
*** As per special request tool can be equipped with seals of up to 175 deg C (350 deg °F)
| SDT-HMJ475 | SDT-HMJ675 | SDT-HMJ800 | SDT-HMJ950 | |
| Nominal OD (A), mm | 124 | 175 | 203 | 241 |
| Thru Bore (B), mm | 55 | 70 | 70 | 76 |
| Free stroke Up, mm | 230 | 230 | 230 | 230 |
| Free stroke Down, mm | 150 | 150 | 150 | 150 |
| Length in fixed position (C), mm | 6 750 | 6 750 | 7 000 | 7 000 |
| Hydraulic delay time, sec | 30 – 150 | 30 – 150 | 30 – 150 | 30 – 150 |
| Nominal Up latch setting, kgf | 25 000 | 59 000 | 70 000 | 75 000 |
| Nominal Down latch setting, kgf | 16 300 | 32 000 | 45 000 | 49 000 |
| Pump Open Area, sm.sq. | 76 | 153 | 198 | 266 |
| Maximum pull during hydraulic delay, kgf | 34 600 | 86 000 | 110 000 | 110 000 |
| Tensile yield, kgf | 177 350 | 320 000 | 365 000 | 543 000 |
| Torsional limit, Nm | 18 000 | 49 000 | 84 000 | 170 000 |
| Connecting threads | NC38 | NC50 | 6 5/8 Reg | 7 5/8 Reg |
| Make up torque, kgf*m | 1 200 – 1 400 | 3 900 – 4 500 | 6 500 – 7 000 | 8 000 – 9 000 |
| Maximum operating temperature, °C | 150 °C | 150 | 150 | 150 |
| Weight, kg | 340 | 874 | 1 300 | 1 850 |
* Actual values are supplied in tool test report
** Tool should be sent for maintenance every 250 hours when used in environment with chloride content higher than 50,000 mg/l
*** As per special request tool can be equipped with seals of up to 175 deg C (350 deg °F)
