The Petroleum Potential of the Late Cretaceous-Palaeogene Sediments of the Reinga, Northland and Deepwater Taranaki Basins

Abstract

Extensive sampling from 15 wells and a set of 2D seismic dip lines located close to the shelf margin of Reinga, Northland and Deepwater Taranaki Basins formed the key datasets for a regional study. Existing biostratigraphic reports and petrophysical analysis of wireline data were reviewed and integrated with new petrographic and geochemical TOC analyses, reservoir quality QEMSCAN analyses and a detailed sequence stratigraphic interpretation, and post-stack seismic inversion. This integrated approach allowed the extrapolation of well analysis across the whole area based on a framework of key sequence boundaries interpreted from Cretaceous through Miocene. Basin modelling was conducted to assess source rock maturity, and reservoir interval porosity was inferred from acoustic impedance via seismic reservoir characterization, enabling quantification of reservoir quality in deeper water away from well coverage. These basins formed near the margin of Gondwana in a mainly Late Cretaceous rift phase that led to the separation of the New Zealand micro-continent from Australia and Antarctica. Two post-rift inversion events have been recorded. Also, the study has identified mass transport systems, including Cretaceous delta complexes, Miocene channels and Miocene deepwater turbidites. All petroleum systems elements are present in the study area: source rock intervals in the syn-rift and early post-rift; clastic reservoirs have been identified and attempts made to quantify quality; regional seal intervals have been identified; traps types include listric faults, four-way dip closures and inversion structures.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015