Deepwater Taranaki Basin, New Zealand—New Interpretation and Modelling Results for Large Scale Neogene Channel and Fan Systems: Implications for Hydrocarbon Prospectivity

Abstract

The deep-water Taranaki Basin, located off the north west coast of New Zealand, is an underexplored, frontier area with one recent exploration well and limited 2D seismic coverage. The basin developed through multiple tectonic cycles, including Mesozoic rifting, followed by Late Cretaceous and Paleogene subsidence associated with seafloor spreading in the Tasman Sea. Large-scale Neogene channel systems that developed throughout the basin provided transport of significant volumes of sediment into the deeper water areas. The channel systems confirm that large fan complexes are likely to be present, however, poorly understood due to the limited extent of 2D seismic coverage. New regional interpretation has been carried out to improve understanding of key stratigraphic sequences, structural elements and basin evolution, providing new insights into the prospectivity of this underexplored region. A key focus of this interpretation was to enhance understanding of the distribution and configuration of the channel systems, providing new insights into prospective potential outboard of the shelfal areas which have been the focus for exploration drilling to date. A significant amount of public domain seismic and well data, primarily covering the shallow water shelfal areas, provided the basis for interpretation in this study. The study was undertaken with an integrated approach, utilizing all available well and seismic data, combining sequence stratigraphy to identify and map key sequence boundaries, seismic reservoir characterization to produce rock property and lithological probability for key seismic lines, and a comprehensive review of previous studies carried out in the area. In addition to new regional interpretation, the study provides detailed mapping of the large Neogene channel systems and encouraging evidence for associated large-scale depositional features beyond the extent of previous exploration.