Detailed paleogeographic evolution of the Bass Basin: Late Cretaceous to present
In this study, a detailed, fine-scale, stratigraphic framework, employing spore–pollen biozones as an age control of potentially suitable hydrocarbon source, reservoir and seal facies has been constructed to provide a better understanding of the basin's paleoenvironmental evolution. Data from various sources, including well completion reports, drill core, cuttings descriptions and seismic sections were collated and analysed. Data from 18 wells were used in order to construct two cross-sections; one extending from the northwest to southeast along the basin and the other extending northeast to southwest. Up to 12 biozones were correlated between the wells. Key stratigraphic units and biozones were then correlated with hydrocarbon source, reservoir and seal and were traced along the basin. New results demonstrate that from the late Maastrichtian the depositional system was dominated by a large tidal inlet or lagoonal system situated between a marine influence towards the northwest and fluvial processes operating in the far southeast. Major hydrocarbon source facies are mainly located within the middle to upper Eocene, upper M. diversus to P. asperopolus biozones in the Eastern View Coal Measures and are generally concentrated in the northwest section of the basin. Potential reservoir and seal facies also appear to be thickest in this region. This new research reveals that from an exploration perspective, risk increases towards the southeast as the concentration of source facies diminishes, and the thickness of potential reservoir and seal facies decreases.
Document Type: Research Article
Affiliations: 1: School of Geosciences, Monash University, Geosciences, Building 28, Room 140, Clayton VIC, 3800, Melbourne, Australia. 2: MEO Australia Limited, Level 23/500 Collins Street, Melbourne, VIC, 3000, Australia. 3: Pietrovin Consultants, 132 Canning Street Carlton, VIC, 3053, Australia.
Publication date: October 1, 2013