Decommissioning of the Northern Endeavour FPSO vessel - Phase 1
Project at a glance
Petrofac Facilities Management Limited was awarded the the Northern Endeavour decommissioning project, Phase 1, by the Commonwealth on 30th March 2022.
The FPSO is permanently moored in 380m of water in the Timor Sea, approximately 550km WNW from Darwin, Australia and 250km ESE from Kupang, West Timor. The FPSO is in block AC/L5 within the Australian Commonwealths Territory of the Ashmore and Cartier Islands.
The Field is in a water depth range between 356m to Laminaria to 410m at Corallina. This requires the use of driverless tie-in and intervention techniques for maintenance, inspection, field development and decommissioning.
The now redundant production system comprises a network of subsea wells tied back to the
permanently moored vessel unit through a system of subsea manifolds, flowlines, umbilicals, and
dynamic risers. Produced oil was stored onboard the vessel and unloaded via offtake tankers
using a tandem mooring system.
The FPSO is shut in with no further production being undertaken. The Facility is depressurised and all wells are shut in with Subsurface Safety Valves (SSSVs) closed. In addition to the FPSO, which can accommodate up to 60 Personnel on Board (POB), the Facility
(i). nine development wells over the two fields;
(ii). subsea infrastructure consisting of flexible flowlines and control umbilicals out to each of
the manifolds, plus rigid spools between the manifolds and wellheads;
(iii). flexible flowlines, risers and umbilical risers with individual buoyancy modules installed;
(iv). nine hybrid mooring legs (3 sets of 3) made up of chain and PE plastic coated spiral
strand steel wires (SSW).
Phase 1 of the Project comprises Disconnection of the FPSO and unmanned tow, including well isolations;
The Procurement Strategy adopted will be based on the goods and services required for the below packages:
Work Package A – Engineering Design and Planning; Work Package B – Operation and Maintenance; Work Package C – FPSO Disconnection; Work Package D – FPSO Sail Away; Work Package E – Monitor and Maintain.
Major work-scopes can be classified as below:
· Waste management– including liquid, hazardous, sludge, mud, food, norms
· Fuel Diesel, aviation, Gas, Lubes & Oils
· Services: Charter flights, Helicopters, Charter vessels (including Standby Vessels, Work boats, Adhoc supply boats), Quayside services including Road transport, Catering services
· Subsea Services: Flushing and Chemical Cleaning services, Light well intervention vessel, Subsea Construction and tow vessels, Subsea engineering services, O&M Crewing Services