Pump · PCP
Stator
A steel tube with an elastomer molded inside it in a double-helix shape. It is the non-moving half of the pump.
What it does
Together with the rotor it forms sealed cavities that travel upward and push fluid to surface.
Basics
| Body | Steel tube |
| Elastomer | NBR, HNBR or FKM by temperature and fluid |
| Geometry | Double internal helix |
| Fails by | Swelling, burning or tearing of the rubber |
Common failures
- Elastomer swelling from incompatible fluid or temperature
- Burned elastomer from running dry (pump-off)
- Abrasive wear from sand
- Tearing or chunking of the rubber
Troubleshooting
- Symptom
- High torque at startup, low efficiency
- Likely cause
- Elastomer swelling
- What to check
- Fluid analysis (aromatics, CO2, H2S) and temperature against the elastomer rating
- Symptom
- Torque spikes, then flow is lost
- Likely cause
- Elastomer burned by running pumped off
- What to check
- Fluid level, speed or pump-off control
- Symptom
- Slow flow decline in sandy wells
- Likely cause
- Abrasive wear
- What to check
- Sand cut, lower speed, larger pump