At the end of the extraction process, all boreholes will be decommissioned.
There are two possibilities:
- suspend – the borehole is closed off with a valve.
- abandonment – putting mechanical and cement plugs at various heights in the borehole. Then the plugs and the conductor are cut off and removed 6 metres below the seabed.
When extraction is complete, all the boreholes are capped. The platform is removed, its anchoring posts are cut away and removed 6 metres below the seabed. This ensures that no fishing gear can get stuck behind them. ONE-Dyas first writes a work plan for this, which must be approved by the State Supervision of Mines. Everything is returned to its original state, which is generally better than before due to the nature development that has taken place.