Slickline · Intervention
Lubricator & Stuffing Box
A long, high pressure pipe mounted on top of the tree, capped by a stuffing box that seals around the moving wire.
What it does
Lets tools enter and leave a pressurized well. The tool string is loaded inside, the lubricator is brought to well pressure, and the top valves of the tree are opened so the tools can go down. Retrieval reverses the sequence.
Basics
| Sits on | Top of the tree, above the wireline valve |
| Length | Enough to hold the full tool string |
| Seal on the line | Stuffing box for slickline; grease injection head for braided and electric line |
| Also used | Heavy wall sections in coiled tubing work |
Common failures
- Packing in the stuffing box wears and leaks well fluid at surface
Troubleshooting
- Symptom
- Fluid weeping at the top of the lubricator during the run
- Likely cause
- Worn stuffing box packing
- What to check
- Tighten or repack with the well isolated below; never work on it under pressure