As a result, the owner, Diamond Offshore, has decided to tow the rig to Eden for repairs.

It now looks likely that drilling of Culverin-1 will be delayed by up to four weeks, but a more accurate spud date depends on the availability of equipment for the rig’s mooring system, which will carry out the repairs, Nexus said.

The company claimed the Vic/P56 joint venture will face “only modest ongoing costs” while the rig is out of service.

This follows another disappointment for Nexus last week, when the Apache-operated Fur Seal-1 well in Vic/P54 failed to encounter any significant hydrocarbons while also using the Ocean Patriot Rig.

Drilling of Culverin-1 will aim to test two prospects – Culverin and Scimitar – which are both defined by 3D seismic data.

Culverin, a large structure at Top Latrobe level in the eastern part of the permit, has the potential to contain 97 million barrels of mean oil reserves, Nexus said.

Underlying Culverin at the deeper Intra Latrobe level is Scimitar, which is 10km north of the Basker Manta fields, and is expected to contain a mixture of oil and gas. The company said it had the potential to contain 63 million barrels of mean oil reserves.

Participants in Vic/P56 and Vic/P49, following the farm-in by the non-operators, will be: Nexus Energy (40%), Korea National Oil Corporation (30%), Seoul City Gas Company (20%) and Anzon Australia (10%).