The first exploration well for a decade in the Maui gas field block will be drilled 40 kilometres off the South Taranaki coast.
Shell Todd Oil Services, which runs the Maui field, is bringing in a drill ship from Singapore in Feburary to sink a single well in the Ruru prospect.
The potential field straddles the Maui and Ruru blocks, but the target is deeper than the currently-producing gasfield which industry estimates say is due to run out in about 2020.
Shell Todd Oil Services general manager Rob Jager says the site was chosen because of reworked seismic data and its proximity to Maui's existing infrastructure.
Mr Jager says existing processing and pipeline capacity could service a smaller gas find with perhaps a five-year lifespan, but a major field would require a rethink.
South Taranaki mayor Russ Dunlop hopes the new oil and gas exploration will attract new jobs and benefit the local dairy industry.