Exhumation Study in the Cooper-Eromanga Basins, Australia and the Implications for Hydrocarbon Exploration

Abstract

The Cooper-Eromanga Basins of South Australia and Queensland are not at their maximum burial-depth due to Late Cretaceous-Tertiary and Late Triassic-Early Jurassic exhumation. The main tool used for estimating the exhumation is the available vitrinite reflectance data. Exhumation studies using compaction analysis have also been compiled in order that exhumation is better constrained. The results suggest that Late Cretaceous-Tertiary exhumation increases eastwards from the South Australia to the Queensland sector of the basins. This study has major implications for hydrocarbon exploration. Predicted maturation of source rocks will be greater for any given geothermal history if exhumation is incorporated in maturation modeling.

Keywords:

• compaction analysis
• source rock maturity
• vitrinite reflectance

Acknowledgment

The present work has been made possible thanks to Santos Ltd. for providing the data and the well completion reports. I warmly thank Prof. R. Hillis and Dr. P. Tingate, University of Adelaide, Australia, for their critical reviews; P. Siffleet and G. Jacquier for fruitful discussions; and D. Warner and M. Zwigulis of Santos Ltd. for suggestions of improvement of this research.

Notes

^a Wells without apparent exhumation values means that no data have been collected (i.e., in vitrinite reflectance).