Surface · Rod Pump
Pump-Off Controller
The surface controller that watches the dynamometer data and stops or slows the pumping unit when the well is pumped off.
What it does
A pump-off controller shuts the unit down for a set time so fluid can build back into the wellbore. A variable speed drive does the same job by slowing the pump instead of stopping it.
Basics
| Reads | Dynamometer card: rod load versus position |
| Options | Pump-off controller or variable speed drive |
| Best for VSD | Low permeability wells and shales with hard to predict inflow |
Common failures
- Wrong idle time, the unit pumps off or leaves fluid behind
- Bad load or position sensor gives a false card
Troubleshooting
- Symptom
- Card shape looks wrong every cycle
- Likely cause
- Sensor or calibration problem
- What to check
- Check load cell and position sensor before changing the setpoint
- Symptom
- Frequent fluid pound between shutdowns
- Likely cause
- Idle time too short
- What to check
- Lengthen idle time or move to speed control