Downhole · Rod Pump
Pump Barrel & Plunger
The downhole pump: a precision barrel (pump chamber) with a plunger that moves up and down inside it on the end of the rods.
What it does
On each upstroke the plunger lifts the fluid column and draws new fluid into the chamber; on the downstroke it passes through the fluid it just took in.
Basics
| Parts | Pump chamber (barrel), plunger, traveling and standing valves |
| Cycle | Repeated thousands of times per day |
| Selected by | Pump diameter, setting depth and rate |
Common failures
- Plunger and barrel wear from sand
- Stuck pump from sand or scale
- Fluid pound damage
Troubleshooting
- Symptom
- Card shows pound on the downstroke
- Likely cause
- Incomplete pump fill
- What to check
- Slow the unit or add pump-off control
- Symptom
- Card shows the pump not moving
- Likely cause
- Stuck pump
- What to check
- Plan a workover; review sand control