Tectonic evolution of the Bight Basin and implications for prospectivity of the Ceduna Delta
About the Course
A multi-disciplinary team has been analysing the tectonic evolution of Australia’s southern margin in the Bight Basin, using the Ion seismic data, gravity modelling, GA deepwater seismic data and the newly available high-quality 3D data across the Ceduna Delta. The goal of the project is to determine the tectonic evolution, particularly in terms of the subsidence history and uplift and erosional pulses recorded on the seismic data in the Ceduna Delta. These events have a significant impact on the hydrocarbon prospectivity.
Interpretation of Ion seismic and regional gravity data defined the deep basin geometry down to the Moho and the GA seismic data were reinterpreted to indicate palaeobathymetry in the now deep-water parts of the basin and the likely facies. A new, fully balanced, decompacted and restored regional section across the delta shows the deposition and deformation through time with emphasis on the erosional events and water depths. Significantly, the sectiosn are restored to paleo-water depth at all times, which significantly changes the basin geometry, the interpretation of facies and migration directions. In addition, a forward model in MoveTM shows how the gravitational collapse structures formed allowing the early delta to propagate. Combining all this information has allowed a model to be developed for the basin evolution which can predict the timing and size of structural traps, the timing of maximum burial and hydrocarbon charge and the direction of charge (landward vs seaward). The final step is full Underworld finite element modelling of the basin to test models of Australia- Antarctica breakup and to predict temperature through time and hence hydrocarbon charge.
Kevin is a structural geologist who has over 30 years’ experience in industry and academia. He worked for BP in Canada and London in their structural specialists group and completed a PhD on the PNG fold belt. He has taught at La Trobe and Melbourne Universities and consulted with many companies in Australia and SE Asia. Kevin worked for 10 years with Oil Search Ltd, until 2016 and now teaches courses and consults throughout SE Asia, and carries out research at the University of Melbourne on Fold Belts and Basin Margin evolution.