Evaluation of the Petrel Sub-basin as a northern Australia CO2 store: future decarbonisation hub?

Abstract

The Northern Australia CO2 Store Project has extended investigations for safe, long-term containment of large volumes of CO2 (up to 100 million tonnes) to support liquefied natural gas and other industries in a decarbonised future. Most natural gas fields in the Petrel Sub-basin and the surrounding region have relatively high native CO2 content. This collaborative project improved storage characterisation, evaluated geomechanical risks and estimated engineering demands necessary to progress the concept to ‘prospect’ and ‘resource’. New data have significantly advanced the geological and structural understanding in the region, improving chrono- and litho-stratigraphic correlations, with new well ties across the basin. However, the re-mapping has thrown up new questions that require additional data (e.g. new stratigraphic wells, 3D seismic data) to address those knowledge gaps. Geomechanical modelling in the area has tested (to extreme levels) the potential impact of injection on faults in the area, further de-risking the likelihood of upward migration and leakage. The region could utilise an abundance of energy and feedstocks in the form of solar, natural gas, hydrogen and CO2 to become a future decarbonisation and industrial hub while managing major emissions with offshore CO2 storage.