2D seismic interpretation of Dun06 projects, Great South Basin, New Zealand

Abstract

DUN06 seismic survey was done in the northern part of the Great South Basin of New Zealand with a total of 3110km of high resolution 2D seismic data by Pacific Titan in 2006. This study focuses on 2D seismic interpretation using Petrel Software to interpret the horizons or geological boundaries of different formations based on the extracted well tops from Toroa well which was drilled in the area of interest. The primary objectives of this study are to deduce the structural and stratigraphic information as well as the trapping mechanism of petroleum system if any. Possible indications of the presence of hydrocarbon were also sorted out. There are seven horizons having age ranging from upper Cretaceous to Eocene. Also, approximately 160 faults were interpreted; with two different strike directions; northwest and northeast striking. Several time and depth structure maps were generated. Upon inspection of the facies on the cross section of the seismic images, they areassumed to be deltaic or river channel deposits. The whole structural deformation is classified as syn-rift and post-rift deformation. The latter is divided into first, second and third post rift event. The first two horizons marked the first post-rift event with transgression followed by a set of delta and river channel indicating regression and second post-rift event. The reservoir unit is determined to be PaleoceneDannevirkeTeurian formation and the Early Eocene Paleocene formation acts as the stratigraphic seal and trap for the reservoir unit.