Oil company Nexen, a subsidiary of CNOOC, has submitted a plan for decommissioning of the Ettrick and Blackbird fields, located in the UK North Sea.
Ettrick field, operated by Nexen, has been producing oil and gas through subsea wells tied back to the FPSO Aoka Mizu.
Blackbird field was also tied back to the Aoka Mizu FPSO.
The company cancelled the FPSO Aoka Mizu contract with Bluewater in May, and the decommissioning of the vessel started in June 2016.
Furthermore, Nexen plans to recover FPSO moorings to shore.
Subsea equipment will be recovered to shore and piles cut to -3 meters.
All buried pipelines and umbilicals will be left in situ, with end sections cut and recovered to shore.
According to the UK government website, the decommissioning campaign could last until 2019/2020 with the subsea infrastructure removal as the final step.
Nexen said it has investigated various alternative production strategies to extend the life of the Ettrick and Blackbird fields, but no viable alternative to decommissioning has been identified.