Threat · Flow Assurance
Paraffin Wax
Heavy hydrocarbon chains in the crude that come out of solution as solids when the oil cools, and stick to the pipe wall.
What it does
The layer grows and narrows the tubing and the flowline, raises backpressure and can end in a full blockage. It forms where the oil cools below its wax appearance temperature, mostly in the upper tubing and in cold flowlines.
Basics
| Forms when | Oil cools below its wax appearance temperature |
| Typical spots | Upper tubing, wellhead, cold flowlines |
| Prevention | Insulation, heat tracing, wax crystal modifiers, dispersants |
| Removal | Hot oiling, solvents, pigging, scrapers |
Common failures
- Tubing or flowline plugged with wax
Troubleshooting
- Symptom
- Wellhead pressure slowly rising while the rate falls
- Likely cause
- Wax building up in the flowline
- What to check
- Pig or hot oil the line and review the inhibitor dose