Oil explorer OMV says the Manaia Field off Taranaki will proceed to commercial oil production in the next few months.
The company says an appraisal well produced a pleasing result and it will press ahead to begin commercial production as soon as possible.
The eight-kilometre well was drilled horizontally from a rig at the nearby Maari Field. It is the longest well ever drilled in New Zealand.
OMV says oil was discovered at the site almost 40 years ago and advances in drilling wells means it is now economically viable to extract it.