WATCH: Helix vessel comes to Australian port ahead of decom job with ExxonMobil

December 5, 2023, by Melisa Čavčić

U.S.-headquartered offshore energy services provider Helix Energy Solutions has confirmed the arrival of its purpose-built DP3 semi-submersible vessel to Victoria’s second largest port, GeelongPort, to prepare for decommissioning work offshore Australia.

Helix Q7000 light well intervention rig; Source: Helix Energy Solutions

Back in January 2023, Esso Australia, a subsidiary of ExxonMobil, hired Helix Energy Solutions’ Helix Q7000 semi-submersible vessel to support decommissioning activities in Gippsland Basin offshore Australia. At the time, the firm explained that the light well intervention vessel used for oil and gas field decommissioning would start its activities in Bass Strait at the end of 2023.

After completing operations in New Zealand, the Helix Q7000 vessel arrived in Geelong, Australia, near Melbourne, to mobilize the ROAM system for the first tranche of decommissioning work in the Bass Strait. Helix highlights that ROAM will act as an environmental barrier, allowing the firm to pull the completion tubing from abandoned wells. GeelongPort also confirmed the arrival of the Helix Q7000 well intervention vessel.

Furthermore, the unit is going to be located at Berth 3 at Lascelles Wharf for approximately twelve days to prepare for deployment into Bass Strait by undergoing a crew exchange and loading critical supplies and equipment for the next decommissioning campaign. Located in Corio Bay, Victoria, GeelongPort is situated 75 kilometers by road southwest of Melbourne and comprises 15 berths across two primary precincts, Corio Quay and Lascelles.

“Well intervention units are an important part of the process of decommissioning oil and gas fields like those in Bass Strait. This includes plugging and abandoning wells, rehabilitating former oil and gas fields, and carrying out monitoring,” emphasized GeelongPort.

The 2019-built Q7000 semi-submersible vessel, which was designed to perform in harsh environments, enables riser-based subsea well intervention and decommissioning operations and is capable of a wide range of production enhancement operations in addition to well-cleanup and field development support.

This vessel is optimized for well decommissioning activities, including well suspension, tubing removal, tree recovery, and seafloor clearance. The unit, which can accommodate 140 people, comes with a variable deck load capacity of about 3,000 metric tons in addition to well intervention and service fluids.

While a 600-metric-ton well intervention tower with active and passive heave compensation is on the upper deck, the large flush deck features a skidding system for well intervention support equipment and tubular storage. The vessel has below deck twin work-class ROV systems, bulk fluids storage, and pumping systems.