Woodside Energy Ltd (Woodside) operates the Enfield field within Production Licence Area WA-28-L, approximately 38 km north of the North West Cape, Western Australia. In 2018 the Nganhurra floating production, storage and offtake facility (FPSO) was utilised to flush, isolate and preserve the Riser Turret Mooring (RTM) and the subsea infrastructure, before the FPSO was disconnected and removed from the Enfield field.
The Nganhurra Operations Cessation Environment Plan (EP) (Revision 10) was revised to allow for inspection and maintenance activities on the RTM while it remained on station. The EP was accepted in March 2022. This revision of the EP (Revision 13) proposes to decommission the RTM by removing it from the title area field and transporting it to shore for recycling and reuse opportunities.
The RTM is planned to be removed using a heavy lift vessel (HLV) to lift the structure in one piece onto a barge for transport onshore. The lifting activities will occur either in the title area or in a sheltered water location, approximately 55-75 km east of the title area, approximately 43 km north of the North West Cape. The decision to commence tow from the title area to a sheltered water location or remove and recover from the title area will be based on metocean forecast conditions to ensure safe tow and recovery operations.
The removal activities are planned for between October 2023 and February 2024. Timing of the activities will be dependent on weather conditions, engineering and vessel availability.