Battery · Surface Facilities
Free Water Knockout
A vertical or horizontal vessel used mainly to remove the free water from the production stream.
What it does
Separates gas, oil and free water, discharging the free water from the bottom. Removing it early matters because free water causes corrosion, hydrates and tight emulsions. The oil and remaining liquids go on to treaters.
Basics
| Also called | FWKO, three phase separator |
| Outlets | Gas, oil, free water |
| Sends liquids to | Treaters |
| Levels held by | Level controllers and control valves |
Common failures
- Sand settling in the bottom; vessels may carry sand jets along the bottom to wash it out
Troubleshooting
- Symptom
- Oil in the water outlet
- Likely cause
- Oil water level not being held
- What to check
- Check the level controller and its control valve