Source rock distribution and maturation history of the Gippsland Basin
Honours Degree 2009
University of Adelaide
Despite the long history of petroleum exploration in the Gippsland Basin, there is still uncertainty regarding the type, distribution and generation history of the source rocks for hydrocarbon accumulations. This thesis investigates the source rocks of the Gippsland Basin.
Passey et al. (1990) developed a practical method for identifying and calculating total organic carbon in organic-rich rocks using well logs, known as the (delta)logR technique. This thesis uses Passey et al.’s (1990) (delta)logR technique to analyse source rocks in 16 wells within the Gippsland Basin in order to identify and map the source kitchens.
Analysis using the (delta)logR technique indicates three source rocks within the Gippsland Basin. These are represented by three biozone layers. The oldest is the Campanian-aged lagoonal/marine T. Lilliei siliciclastic source rock. The F. Longus is a Maastrictian-aged lower coastal plain deposited siliciclastic source rock. The youngest is the L. Balmei Palaeocene-aged upper coastal plain deposited source rock which is primarily coal derived.
Burial history models developed for the Hermes-1, Veilfin-1 and Volador-1 wells indicate that the first generation of hydrocarbons was from the T. Lilliei source rocks during the Paleocene (approx 60 Ma). This was followed by generation from the F. Longus source rocks during the late-Eocene (approx 35 Ma) and from the L. Balmei source rocks during the mid-Miocene (approx13.5 Ma).