Downhole · Flow Assurance
Downhole Capillary Injection
A small tube run outside the tubing that takes the chemical from the skid at surface down to an injection point near the pump or the perforations.
What it does
Puts the inhibitor where the problem starts, before deposits form in the tubing. The line, clamps and fittings are the same ones shown as the Chemical Injection Line on the Completions page.
Basics
| Treats | Scale, asphaltenes, wax, corrosion |
| Line | Seamless capillary tubing |
| Ends in | Check valve or injection mandrel |
| See also | Completions, Chemical Injection Line |
Common failures
- Capillary line plugged or crushed, so no chemical reaches bottom
Troubleshooting
- Symptom
- Injection pressure climbs while rate drops
- Likely cause
- Plugged capillary or injection valve
- What to check
- Flush the line and check chemical compatibility