Spatial And Depositional Analysis Of Middle Cambrian Hydrocarbon Prospects In The Southern Georgina Basin, Northern Territory
Bennett, Bradley S.
Geoscience Honours Degree, 2011
University of Adelaide
In recent years the middle Cambrian succession in the southern Georgina Basin, in the Northern Territory has been generating interest for hydrocarbon exploration. To improve the understanding of the petroleum system a spatial and depositional analysis of the key source rock and potential reservoir intervals in the region is required; these are the Arthur Creek “Hot Shale” and Thorntonia Formation respectively.
Ten stratigraphic cross sections of the middle Cambrian sequence have been generated and populated with detailed lithology descriptions in order to spatially assess the interval features. Top surface, 3D maps and facies maps were subsequently created in order to characterise the spatial trends of the formation and the formation features.
The study indicates an optimal source zone in the Arthur Creek “Hot Shale”, which is an interval of thicker, slightly interbedded and highly organic rocks, and the depositional setting across the Thorntonia Formation, which has a relationship with regional reservoir quality. The variations in lithology and lithofacies observed throughout the region were likely caused by changes in depositional energy and setting, which could be a result of sea level perturbations affecting the sediment source and supply within the intractratonic depocentre.
The trends within the lithology and lithofacies of the Arthur Creek “Hot Shale” and the Thorntonia Formation indicate conventional hydrocarbon system features are optimised in the region at the intersection of the two classified zones. Prospective unconventional zones within the Arthur Creek “Hot Shale” are constrained within the optimal source region.