WATCH: Heerema’s giant vessel takes Woodside’s latest decom ‘milestone’ to recycling yard

Australian energy giant Woodside has made further progress in decommissioning and dismantling activities at a field off the coast of Western Australia. Thanks to Heerema Marine Contractors’ heavy lift vessel, a riser turret mooring (RTM) has now reached the Australian Marine Complex (AMC), where it will be prepared for recycling and reuse opportunities.

Woodside is decommissioning the Griffin field, which is located approximately 65 km northwest of Onslow and 94 km northeast of Exmouth in around 130 meters of water depth. While in production, the field comprised the FPSO Griffin Venture with 12 production wells, permanently plugged in 2017, from the Griffin, Scindian, and Chinook reservoirs routed to the riser turret mooring via flexible and rigid flowlines.

While oil products were stabilized and stored for offloading via tanker, gas was transported to the shore via the Griffin gas export pipeline (GEP) for the domestic market. After the field ceased production in 2009, the Australian giant started putting its decommissioning plans into action. To this end, the firm handed out a batch of decommissioning deals to multiple players.

This enables Transocean, TechnipFMC, Heerema, McDermott, Fugro, DOF, and McMahon to participate in the removal and disposal of subsea infrastructure from several oil and gas fields offshore Western Australia, including Griffin.

The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) accepted Woodside’s environment plan on November 21, 2023, enabling it to undertake closure of the Griffin field facilities.

A few months later, NOPSEMA gave Woodside’s green light to permanently decommission in situ the subsea infrastructure at the field, including up to 11 of the 12 riser turret mooring anchors and associated anchor chains, five piled foundation structures, and six concrete gravity bases.

Woodside has now confirmed the removal of the Griffin riser turret mooring. Heerema Marine Contractors’ Aegir heavy lift vessel transported the RTM to the Australian Marine Complex, where it is being cleaned and deconstructed in preparation for recycling and reuse opportunities.

The Griffin project supplied 62 billion cubic feet of gas to power Western Australia’s homes and industry, as well as 167 million barrels of oil during its lifetime. Madeleine King, Australia’s Minister for Resources, joined Woodside personnel to witness the arrival of the Griffin RTM at AMC Henderson.

Ragan Stonier, Woodside VP Projects Australia, described the removal of the RTM as a demonstration of the company’s continued commitment to decommissioning projects in a safe and environmentally responsible manner.

“The Griffin RTM removal is another milestone for Woodside in our decommissioning journey, which so far has seen the removal of approximately 25,000 tonnes of infrastructure including more than 200 kilometres of pipe and 100 subsea structures across the Enfield, Echo Yodel, Stybarrow and Griffin fields. Additionally, 20 wells have now been permanently plugged,” highlighted Woodside.