Downhole · PCP
Sucker Rods
A string of steel rods screwed together that connects the drive head to the rotor at the bottom.
What it does
Transmits rotation and torque from surface to the pump. Centralizers keep them off the tubing wall to cut wear.
Basics
| Types | Conventional with couplings, or continuous |
| Loads | Torque plus axial weight |
| Wear control | Rod guides / centralizers |
Common failures
- Rod on tubing wear in deviated sections
- Torsional or fatigue breaks (parted string)
- Coupling wear
Troubleshooting
- Symptom
- Torque drops to near zero, drive spins free
- Likely cause
- Parted rod string
- What to check
- Plan a fishing job; review torque history for overloads
- Symptom
- Tubing holes at repeated depths
- Likely cause
- Rod on tubing wear
- What to check
- Centralizer placement against the deviation survey