Downhole · Gas Lift
Side Pocket Mandrel
A tubing joint with an offset pocket that holds a gas lift valve outside the main flow path.
What it does
Connects the annulus to the tubing through the valve and lets crews swap valves by slickline or coiled tubing without pulling the string.
Basics
| Valve change | Slickline or coiled tubing with a kickover tool |
| Seals | Valve seals on a polished bore inside the pocket |
| Advantage | Pocket offset keeps the valve out of the flow and solids |
| Alternative | Conventional mandrels, valve retrieved only by pulling tubing |
Common failures
- Valve not latched, falls or leaks
- Damaged polished bore that will not seal
Troubleshooting
- Symptom
- Gas passing at the wrong depth
- Likely cause
- Valve not set or latch failed
- What to check
- Run slickline to check and reset the valve