Can you imagine if primary and secondary well control are failed? Well is flowing all the time so how can we deal with this situation? For this situation, you must use Tertiary Well Control.
Tertiary Well Control is specific method used to control well in case of failure of primary and secondary well control. These following examples are tertiary well control:
- Drill relief wells to hit adjacent well that is flowing and kill the well with heavy mud.
- Dynamic kill by rapidly pumping of heavy mud to control well with Equivalent Circulating Density (ECD)
- Pump barite or gunk to plug wellbore to stop flowing
- Pump cement to plug wellbore
Reference book: Well Control Books