Workover · Intervention
Workover Rig
A truck mounted mast with a hoist that pulls and runs tubing, rods and downhole pumps in an existing well.
What it does
Does the heavy work that lines cannot: changing a rod pump, PCP or ESP, replacing leaking tubing, repairing the completion. When the well cannot be killed, a snubbing unit pushes pipe in against pressure instead.
Basics
| Also called | Service rig, pulling unit |
| Typical jobs | Pump changes, tubing and rod replacement, completion repair |
| Live well option | Snubbing unit |
| Before starting | Well killed or isolated, BOP installed |
Common failures
- Repeat pump failures that keep the rig coming back
Troubleshooting
- Symptom
- Same well needs a workover every few months
- Likely cause
- Root cause not fixed, for example rod wear, sand or wrong pump size
- What to check
- Inspect pulled equipment and run a failure analysis before reinstalling