“We already knew there were a heck of a lot of sediments in the Northland Basin, but now we know this could turn out to be a brand new petroleum system, which is very positive,” GNS spokesman Chris Uruski told EnergyReview.Net from Wellington today.

GNS geoscientists had identified over 20 possible drilling targets off the west coast of Northland, five of which were about 100 square kilometres in area, roughly equivalent in size to the Taranaki Maui field. The number of targets conformed to a bell-curve distribution, with a handful of very big targets, a lot of medium-sized ones, and a scattering of possible small plays, he said.

Last November Associate Energy Minister Harry Duynhoven announced that Crown Minerals had called in specialist British seismic contractor Spectrum Energy & Information Technology to help it and GNS prepare an offshore Northland bidding round later this year.

Spectrum has already reprocessed 9000km of seismic from the Northland Basin and GNS is preparing a detailed prospectivity report that will be marketed to the international oil and gas exploration community in the next two to three months.

The 120,000 sqkm Northland Basin has similar geology to the adjacent Taranaki Basin and total sediment thickness over much of the basin ranges between 4km-6km, with localised pockets exceeding 7km. Cretaceous coal source rocks are capped by marine sandstones and mudstones.

Uruski said last year’s Karewa-1 well, drilled on the edge of the Northland-Taranaki basins by ConocoPhillips, had yielded sufficiently interesting results for partner Todd Energy to apply for a small prospecting permit the Kawera-1 well site. Also, Todd was granted two new licences immediately to the south earlier this month.

Uruski is to give a paper on the Northland project at next month’s New Zealand Petroleum Conference.