Helix vessel close to crossing the finish line at decom job offshore Australia

U.S.-headquartered offshore energy services provider Helix Energy Solutions is drawing to an end its multi-well decommissioning assignment offshore Australia, which is being carried out with its purpose-built DP3 semi-submersible vessel.

After wrapping up work in New Zealand, the Helix Q7000 semi-submersible arrived in Australia to support decommissioning activities in the offshore Gippsland Basin. The vessel is slated to complete its decommissioning program with Cooper Energy this week. The work on the Basker Manta Gummy (BMG) project has reached the decommissioning of Basker-6, the last well of the BMG decommissioning campaign.

Once the activities at the well are completed, the Helix Q7000 vessel is due to come off-hire this week. According to Cooper Energy, the expected final cost of the BMG wells decommissioning program remains toward the upper end of the mid-case estimate range of A$240 – 280 million (almost $159.4 – $185.93 million).

The company explains that a future stage of work will be required to remove seafloor production equipment, which can be conducted with a workboat as it represents a significantly smaller scope than the multi-well decommissioning program.

Furthermore, Cooper continues to pursue its claim in the Supreme Court of Victoria against Indonesian state-owned enterprise PT Pertamina Hulu Energi (Pertamina) for the latter’s 10% share of the BMG decommissioning costs.

The claim is said to encompass interest on the costs to date and future costs associated with the remaining scope of work. An interlocutory hearing has been scheduled for late July 2024, regarding service of the writ and statement of claim.

As Pertamina, via its Australian subsidiary, participated in the BMG oil project during its production life, Cooper Energy explains that its claim concerns the Indonesian player’s obligations under the withdrawal and abandonment provisions of the oil project joint operating and production agreement.

Australia’s National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) greenlighted Cooper’s plan for the first phase of decommissioning activities at the BMG project in 2022. Helix Energy Solutions’ Q7000 light well intervention unit was hired in April 2021 for the scope covered by the first stage of the decommissioning campaign.

The 2019-built Q7000 semi-submersible vessel, 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.

Helix is also busy with work outside Australia, as confirmed by the resumption of cable operations at the Greenlink interconnector that will link Ireland and Wales. The company also won a long-term joint decommissioning agreement with Talos Energy in February 2024.

In addition, Helix recently secured a contract for deepwater well intervention with Esso Exploration and Production Nigeria (ESSO) for a project offshore Nigeria, which came shortly after the U.S. player’s decommissioning contract in Brazil was extended by Trident Energy.