Breaking new ground ? again! The Pegasus sub-basin of the East Coast Basin, North Island, New Zealand

Abstract

The New Zealand government has recognised that the 5.7 million km2 of its marine estate may contain valuable petroleum reserves. To investigate this possibility and to encourage development of those potential reserves, a series of reconnaissance 2D seismic surveys across virtually unknown sedimentary basins is in train. So far, every survey has indicated thick sedimentary successions, the basic ingredient for petroleum generation. Each basin targeted by new data is at a different stage of development; the Great South Basin is licenced to groups led by ExxonMobil and OMV. Deepwater Canterbury is being explored by Anadarko and Origin. Deepwater Taranaki is licenced to Anadarko, Hyundai, AWE, Global and RCT. A licence round closed recently on the Raukumara Basin, while the Reinga and Northland basin round will close in mid-2010. The latest survey was across the Pegasus Sub-basin of the East Coast Basin. It, too shows extensive thick sediments and a licencing round is expected to be announced in early 2011. The Pegasus sub-basin lies at the southern end of the 800 km long East Coast Basin of North Island, New Zealand. It currently occupies the transition zone between subduction of the Pacific plate below the Australian plate along North Island and the strike-slip boundary through South Island. An early seismic line across the region showed a thick succession of relatively undeformed sediments occupying this sub-basin. In early 2010, the Crown Minerals unit of New Zealand?s Ministry of Economic Development commissioned a 3,000 km 2D survey across the region. This paper describes the initial results of that survey