New Zealand is preparing for a petroleum exploration permit bidding round in the offshore Northland basin.
Planning for next year's bidding round is underway, though permit boundaries have not yet been confirmed.
According to Associate Minister of Energy Harry Duynhoven, the basin's proximity to the productive Taranaki basin is a selling point. "Initial interpretation, together with the results of Wakanui-1, show that the Northland basin is highly prospective," Duynhoven said.
In preparation for the bidding round, the Ministry of Economic Development's Crown Minerals Group joined forces with the Institute of Geological and Nuclear Sciences (GNS) and UK-based seismic contractor Spectrum Energy & Information Technology to produce a data package on the basin's petroleum prospectivity.
Spectrum has agreed to reprocess 9,100 km of seismic data from the basin. The data includes a 1,600-km 1982 survey, acquired by Geco, and a 7,500-km survey acquired by Conoco and partners in 1995. Test lines show significant enhancements in data quality and imaging over the original processing.
Spectrum has also entered into an agreement with GNS, which will prepare an interpretation and hydrocarbon potential report based on the reprocessed data. The data will provide explorers with an understanding of the stratigraphic framework, petroleum systems, play concepts, and trap types of the Northland basin. The package will incorporate a revised understanding of the basin's nearshore potential by using recently released data obtained from the deepwater Wakanui-1 well, drilled off the continental shelf in 1999.
Initial interpretation from Wakanui-1 shows that the Wakanui structure is not buried by marine Cretaceous rocks as previously believed. The presence of a Middle Jurassic coal measure succession strongly suggests the presence of a new previously unsuspected petroleum system.
Seismic data suggests that the depocentre to the east of the Wakanui structure contains both Jurassic and Cretaceous source rocks and thermal modelling suggests that they are buried deep enough to be generating and expelling hydrocarbons.
Reprocessing should be complete by the end of January 2004, following which the interpretation report will be completed ahead of the anticipated bid round.
11/05/03