Conceptual model of the Lower Permian Kingia Sandstone (northern Perth Basin, Western Australia) as an alternative energy resource

Abstract

The geothermal potential of the Kingia aquifer in the northern Perth Basin has been identified. In order to further assess resource potential, the occurrence, conditions, and properties of the Kingia Sandstone have been considered further. A new regional correlation supports the Kingia Sandstone being a regionally extensive unit deposited along the northern margin of the syn-depositional Dandaragan Trough. The unit is part of a falling-stage to lowstand system containing lower and upper shoreface, coastal, beach, and estuarine sands. Gross Kingia Sandstone thickness varies from 16 m on flanking terraces to at least 71 m in the basin depocenter. At depth, reservoir properties are preserved where iron-rich clay grain coatings inhibit cementation and preserve primary porosity. In such cases, net reservoir ranges from 3 to 58 m thick (18 m mean) and net porosity range is 12–19 p.u. (15 p.u. mean). The prevailing geothermal gradient is ~37°C/km with heat flow in excess of 90 mW/m2. Resultant Kingia aquifer temperatures exceed 115°C. Given the presence of hot, porous Kingia aquifer, the potential for geothermal power generation is strong. Production of Kingia brine to surface facilities allows for power conversion via established binary Organic Rankine Cycle (ORC) technology. A scalable Kingia opportunity could help to meet Western Australia’s decarbonisation aspirations by contributing to the replacement of coal-fired and gas-fired power plants, plus supply of low-carbon power to local urea, hydrogen, and gas projects. An enhanced understanding of Kingia porosity distribution, reservoir compartmentalisation, flow performance, and ultimate energy delivery remain key uncertainties subject to future de-risking activities.