The 172mm TZ Brand HDD Mud Motor (Model: 172-78-5-914) is a premium, high-performance downhole motor engineered specifically for challenging Horizontal Directional Drilling (HDD) and underground boring utilities. Featuring an optimized 7:8 lobe configuration and a powerful 5-stage design, this 6.75-inch tool delivers massive output torque and high mechanical efficiency. All technical performance matrices are fully validated based on official motor DYNO testing data to ensure ultimate reliability and premium rate of penetration (ROP) in rock and complex formations.
1. Motor Dimensions & Physical Specifications
| Specification Parameter | Metric System | Imperial System |
|---|---|---|
| Tool Outer Diameter (Tool OD) | 172 mm | 6.75 in |
| Lobe Configuration | 7:8 | 7:8 |
| Stages | 5 | 5 |
| Length A | 768 mm | 30 in |
| Length B | 1954 mm | 76.9 in |
| Length C | 8090 mm | 318 in |
| Total Weight | 1000 kg | 2200 lbs |
| Recommended Bit Size | 213 – 251 mm | 8 3/8″ – 9 7/8″ |
| Top Connection Thread | 4 ½ REG | 4 ½ REG |
| Bit Connection Thread | 4 ½ REG | 4 ½ REG |
2. Motor Performance & Dynamic Operational Limits
| Operational Feature | Metric System | Imperial System |
|---|---|---|
| Mud Flow Range | 1183 – 2366 lpm | 312 – 625 gpm |
| Rotation Ratio | 0.071 Rev/Lit | 0.269 Rev/Gal |
| Speed Range | 84 – 168 rpm | 84 – 168 rpm |
| Working Differential Pressure | 4.0 MPa | 585 psi |
| Max Differential Pressure | 5.65 MPa | 824 psi |
| Output Torque | 7176 N.m | 5293 lbs-ft |
| Maximum Stall Torque | 10137 N.m | 7476 lbs-ft |
| Max Output Power | 150 kW | 200 hp |
| HSG Max Allowable Pull | 1935 KN | 434,830 lbs |
| Bit Max Allowable Pull | 1370 KN | 307,860 lbs |
3. Key Applications & Geological Suitability
This 172mm downhole motor is purpose-built to deliver steady directional control and high cutting removal efficiency in major utility installations:
Geological Formations: Highly effective in medium to hard rock formations, complex gravel layers, cemented sandstones, and abrasive shales.
HDD Utility Crossings: Perfectly optimized for long-distance river crossings, highway under-boring, and municipal oil/gas/water pipeline installations.
Steering Performance: Provides absolute steering stability when paired with mud-pulsed wireless MWD or wireline steering grid systems.
4. Optional Configurations & Customization
To align with diverse drilling rig capabilities and target bit profiles, we offer tailormade structural sub-assemblies:
Housing Types: Available in both Fixed Bend Housing (for standard aggressive builds) and Adjustable Bend Housing (0-3° range for highly versatile steering adjustments).
Rotor/Stator Cores: Custom elastomer compounds are available for oil-based muds (OBM) or ultra-high-temperature deep wells.
Catch Device: Built-in premium rotor catch assembly comes standard to eliminate the risk of leaving components downhole.
5. Best Practices for Field Operations & Maintenance
Mud Quality Control: Sand content in the drilling fluid must be maintained below 1% to prolong the active lifespan of the stator elastomer and thrust bearings.
Pressure Management: Avoid abrupt pressure surges. Gradually ramp up the mud pumps to hit the recommended working differential pressure of 4.0 MPa.
Post-Drill Service: Always flush the motor interior thoroughly with clean water immediately after pulling out of hole (POOH) to clear residual solid build-ups.