McDermott has revealed details about an offshore decommissioning contract it secured with Woodside Energy in May for work to be carried out in Western Australia.
McDermott announced on 10 July that it had secured an engineering, procurement, and removal contract with the Australian energy giant for the full removal of the Stybarrow disconnectable turret mooring (DTM) buoy, as part of the decommissioning of the Stybarrow field located in the northwest Cape.
The company is set to provide project management and engineering services for the recovery, transportation and offloading of the DTM buoy to a suitable onshore yard facility for dismantling and disposal.
The DTM buoy will be lifted and removed using McDermott’s DLV2000 vessel.
The company’s Perth-based team will oversee project management, while engineering and fabrication support will be provided by the team in Kuala Lumpur, Malaysia, and Batam, Indonesia.
“This award not only demonstrates McDermott’s proven track record in undertaking deepwater projects of diverse scopes, but it also highlights the critical importance of decommissioning in the offshore industry,” said Mahesh Swaminathan , McDermott’s Senior Vice President, Subsea and Floating Facilities.
“With our seamless integration of engineering, fabrication, and offshore mobilization expertise, we believe we are well-equipped to execute this project efficiently and responsibly, ensuring the safe recovery and removal of the Stybarrow DTM buoy.”
While the Stybarrow field was still in production, it comprised the MODEC-operated FPSO Stybarrow Venture MV16 – capable of processing 100,000 barrels of liquids per day and a storage capacity in the order of 900,000 barrels – with production, gas injection and water injection wells at four drill centers routed to the DTM via flexible flowlines. During that time, oil products were stabilized and stored for offloading via tanker.
Production from the field started in 2007 and ceased in June 2015. Since then all flowlines and gas lift lines were flushed and filled with treated seawater and production flowlines disconnected, while all production, gas injection and water injection wells were shut-in and capped to await plugging and abandonment.
After Stybarrow Venture was disconnected from the DTM and demobilized from the field, the DTM unexpectedly sunk to the seabed at some point between May 2016 and October 2016, where it lies in a water depth of approximately 825 meters with risers still attached. Following the DTM sinking, the riser buoyancy modules were removed to eliminate any buoyant risk.