Revisiting the upper Permian of the northern Perth Basin (integrated study)

The northern Perth Basin has long been regarded as a proven and mature hydrocarbon province undergoing progressive field depletion (e.g. Dongara, Yardarino, Mondarra, Beharra Springs, Woodada) of mostly upper Permian sandstone and limestone plays at depths 1600–3300 m since first production in the 1970s. The basin’s prospectivity has, however, been considerably revitalised in the past 10 years following discovery of the Waitsia Field and some of the largest conventional onshore reservoirs in Australia hosted in previously marginally appraised lower Permian plays.

Renewed petroleum activity in the northern Perth Basin has unsurprisingly led to focus exploration endeavours on the lower Permian reservoirs. Nevertheless, a 2MMscfd gas flow rate in Strike Energy’s L24 (2022) and two oil discoveries representing 20.5 MMboe (2C contingent resources) in Mineral Resources’ EP426 (2023–2024) in the upper Permian Dongara–Wagina sandstones demonstrated porosity preservation at depth >3000 m and untapped economic potential in areas that were previously considered high-risk and unattainable.

Despite the recent discoveries, considerable uncertainties remain as to the spatial distribution of late Permian facies belts, the depositional and structural controls that drove sediment deposition, and the stratigraphic evolution of the upper Permian succession. Ferdinando and Longley (2015) identified that nearly a quarter of dry wells targeting upper Permian plays are due to a lack of porous reservoir lithologies.