North Taranaki Basin Potential Evaluation Using AVO and Seismic Attributes

Abstract

The North Taranaki basin is located north of the Taranaki Peninsula offshore the west coast of the northern island of New Zealand (Figure 1). For decades there has been exploration activity in the North Taranaki Basin with no commercial success. Numerous wells have encountered both oil and gas accumulations proving the presence of a working petroleum system. Most wells have been drilled on sparse 2D data, where identifying large structural highs in the presence of a working petroleum system would typically yield positive results. Modern 3D seismic data and high resolution AVO products are suggesting that prospective areas are yet to be tested in this Basin. A modern broadband, long-offset 3D survey was designed and acquired to assess the structural uncertainty in the area and provide much more detailed understanding of the petroleum system. The survey enabled detailed interpretation and mapping of potential reservoirs. This investigation evaluates the hydrocarbon potential of the basin using the newly acquired data and an advanced AVO workflow to derive and seismic attributes and rock properties for interpretation. The broadband and long-offset 3D seismic data enables creation of angle substacks that can be qualitatively analyzed for AVO effects (Figure 2 – Sweetness), as well as input to a quantitative pre-stack seismic inversion to obtain elastic properties to identify lithology distribution. Under favorable porosity conditions the influence of pore-fluid can also be discernable. The advanced AVO workflow employed for the North Taranaki survey challenges the existing interpretation and provides unique insights that have uncovered potential for material hydrocarbon accumulations.

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