About 10km north of the Tui Area oil project in 125m of water, the well has a planned total depth of 4060m.

With a mapped closure extending over 30 square kilometres, it could hold more than 100 million or more barrels of oil, according to AWE.

At 6am New Zealand time on Tuesday, the Ocean Patriot drilling rig was preparing to drill ahead after cementing surface casing at a measured depth of 234m.

AWE’s 50% interest is fully carried for the budgeted costs of the Kopuwai-1 well as a result of recent farmouts to Beach Petroleum (20%) and Mitsui Exploration (30%).