Northern Offshore and EnQuest have submitted combined decommissioning programmes for the Northern Producer FPF float-off and disconnection of risers and pipelines to the UK authorities.
The Northern Producer is a floating production facility (FPF) producing on the EnQuest-operated fields in the UK North Sea. It is operated by EnQuest as the duty holder but owned by Northern Offshore’s Qualimar Shipping Company.
The decommissioning programme in respect of the FPF has been prepared by EnQuest for and on behalf of Qualimar Shipping Company.
EnQuest, as pipeline owner, has also prepared the decommissioning programme in respect of relevant pipelines. This decommissioning document, containing both programmes, is submitted jointly by Qualimar and EnQuest.
The combined decommissioning programmes include the departure of the Northern Producer FPF, the removal of the associated riser systems from the Don South West, and West Don fields, and clearance of the 500m safety zone.
The FPF will be used for initial decommissioning activities such as flushing or de-oiling of the subsea infrastructure and to support the implementation of positive isolations for the wells.
Once these activities have been completed the vessel will depart the field.
The Northern Producer is an AKER H3 semi-submersible unit originally constructed by Trosvik Framnaes in Norway in 1976. In 1996 the vessel was purchased by Northern Offshore.
Since May 2009, the semi-sub unit has provided the export route for the Don South West, Conrie Ythan, and West Don fields that are situated within Blocks 211/13b, 211/18a, and 211/18e of the Northern North Sea sector of the UKCS and operated by EnQuest.
These fields are located approximately 527km north-north-east of Aberdeen in water depths between 165m and 178m.
The Cessation of Production documentation for these fields is currently under consideration by the Oil and Gas Authority.
After the Northern Producer departs the field, Northern Offshore will pursue and possibly secure alternative arrangements for the redeployment of the FPF.
Under the decommissioning programs, complete removal of the Northern Producer FPF is planned and mooring and anchor systems will be recovered to shore for reuse, recycling or disposal.
The riser system and pipeline sections within the 500m zone will be disconnected and recovered to shore.
Exposed concrete mattresses and grout bags will be recovered to shore for re-use, recycling or disposal. Existing rock will remain in situ.