Pump · ESP
ESP Pump
A multistage centrifugal pump. Each stage is a rotating impeller and a fixed diffuser; stacking stages builds the pressure needed to lift fluid to surface.
What it does
Adds head stage by stage. Flow depends on stage design and speed; head depends on the number of stages.
Basics
| Type | Multistage centrifugal |
| Stage designs | Radial (low flow) or mixed flow (high flow) |
| Stage material | Typically high nickel cast iron |
| Assembly | Floater or compression stages |
| Series | Named by housing OD, e.g. 400 = 4.00 in |
| Typical rate range | About 100 to 30,000 bbl/d |
| Economic limit | Usually not economic below about 150 bbl/d |
| Testing | API RP 11S2 |
Common failures
- Abrasive wear from sand
- Scale or asphaltene plugging the stages
- Gas lock
- Upthrust or downthrust wear from running outside the operating range
- Broken shaft
Troubleshooting
- Symptom
- Low flow with low amps
- Likely cause
- Gas interference, worn pump or tubing leak
- What to check
- Intake pressure, pressure test tubing, check gas handling
- Symptom
- Low flow with high amps
- Likely cause
- Viscous fluid, emulsion or plugged stages
- What to check
- Fluid sample, chemical treatment, review stage selection
- Symptom
- No flow, motor running normal amps
- Likely cause
- Broken shaft
- What to check
- Confirm with shaft rotation checks before pulling