Shortly before arriving at the project on September 12, one of the vessel’s four thrusters malfunctioned. While the joint venture scrabbled to assess whether it was safe to operate with only three thrusters, a second one blew six days later on September 18.

Origin said the vessel, contracted to provide accommodation for maintenance and trades personnel on the Yolla A platform, had now gone to Port Phillip Bay for repairs.

The Safe Concordia could take up to six weeks to repair, which would mean the vessel could not return to the Yolla platform until early November. The owners of the vessel are responsible for the cost and execution of repairs, said Origin.

Delays to schedule and initial production from the BassGas project are likely, with Origin reporting that a full impact assessment was still being looked at.

This drama is the latest in a string of bad luck for the project, which is more than a year behind schedule.

Originally expected to cost A$450 million, the project has since blown out to $500 million and could still cost considerably more.

Project operator Origin is also locked in a legal feud with Clough Engineering, over major cost overruns and delays. The case will determine how much financial responsibility the equity partners and Clough should each bear, and could take more than two years to resolve.

Meanwhile, joint partner Australian Worldwide Exploration has this month announced it will fork out A$37 million on BassGas cost overruns from the $120 million recently raised through a placement of ordinary shares.

BassGas is a partnership between Origin Energy as operator (42.5%), AWE (30%), CalEnergy (15%) and Mitsui subsidiary Wandoo Petroleum (12.5%)