Northland Basin

Key facts

Where

A mainly offshore basin of over 50,000 sq km along the west coast of the northern North Island.

Geology

Contiguous with Taranaki Basin to the south, with up to 9,000 m of Jurassic to Quaternary basin fill.

Wells drilled

Only two significant exploration wells drilled: Waimamaku-1 (onshore, 1969), and Wakanui-1 (offshore, 1999). Karewa-1 (offshore, 2003) was drilled in the far northeast of the adjoining Taranaki Basin.

Known hydrocarbons

Late Cretaceous allocthonous oil shale outcrops onshore, gas seeps, gas shows in Waimamaku-1 and -2.

Prospects

Strong geological similarities with Taranaki Basin but virtually unexplored.

Potential source rocks

Jurassic and Cretaceous coal measures, Cretaceous to early Cenozoic marine mudstones, possible Cretaceous to Eocene coal measures.

Potential reservoir rocks

Late Cretaceous terrestrial-paralic-nearshore sandstones, Eocene turbidites, Miocene volcaniclastics and turbidite sandstones.

Downstream infrastructure

Oil refinery and port at Marsden Point, Whangarei, with connections to the North Island gas pipeline network and a liquids pipeline to Auckland.

Auckland region gas consumers

Otahuhu B 380 MW; Southdown freezing works gas/cogen 118 MW; planned Otahuhu C (2006) 400 MW. Connection to high-pressure pipeline to Huntly power station gas/coal 1000 MW.

Port facilities

Marsden Point, Whangarei, is the deepwater port for the New Zealand Refining Company's oil refinery. The jetty can take tankers of up to 145,000 tonnes displacement.

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• Northland Basin Exploration Potential [1.1 MB PDF]
• Northland Basin map