Reservoir Quality of the Northwest Shelf of Australia in a 3rd Order Sequence Stratigraphic Framework.

Abstract

The Northwest Shelf of Australia is a prolific hydrocarbon province. Over the coming years, a number of multi-tcf gas discoveries (made since the 1960's) will come online through a series of LNG developments. In this province high quality reservoirs exist within Triassic, Jurassic and Cretaceous stratigraphy. Potential for further significant discoveries remains with a number of untested leads identified in the published literature. This study investigates the differences between the reservoir quality of lowstand, transgressive and highstand systems tract deposits on the Northwest Shelf, focusing on the key Mesozoic stratigraphic intervals within the Browse and Bonaparte basins. To accomplish this we integrate a number of spatially and temporally enabled datasets: reservoir properties, plays and leads, tectonic elements and geodynamically reconstructed gross depositional environment maps. All of the datasets are temporally constrained by a biostratigraphically calibrated, global, 3rd-order sequence stratigraphic Earth Model. Integration of these datasets allows reservoir quality relationships to be linked to the controlling environmental and tectonic settings at the time of deposition, as inferred from the gross depositional environment and tectonic element maps. These can provide potential insights into sediment provenance and its importance in controlling the commercial viability of a reservoir. The study should indicate that reservoirs of a particular systems tract are typically of a higher quality, as well as demonstrating stratigraphic and spatial variations in reservoir quality over the study area. The combination of these varied datasets also provides a framework that helps to predict the best reservoirs, which in turn can be used to prioritise leads for further study. This initial study will provide the groundwork for the data to be integrated into a three-dimensional depth grid, which will allow for a more detailed interrogation of all aspects of the fields and plays in a regional setting.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014