The Kahu-1 exploration well off the Taranaki coast is being abandoned, after no oil was found.
The 3835 metre deep well, which is about 3km east of the Tui oil field, is now being plugged.
Once complete, the Kan Tan IV drilling rig will move to a joint venture drilling the Tuatara-1 exploration well.
Shares in New Zealand Oil & Gas, which is a 12.5% partner in the well, fell 3 cents to $1.22 on Monday.
Shares in 10% partner, Pan Pacific Petroleum, were unchanged at 20 cents.