b'Geophysics in the surveysNewsGeological Survey of Victoria: Update on projectsHydrogen storage potential inVictoriaThe Geological Survey of Victoria (GSV) has completed a preliminary investigation of the underground hydrogen storage (UHS) potential of operating, depleted and unproduced gas fields in the Otway Basins Port Campbell Embayment.The existing operations and infrastructure in the Port Campbell Embayment make it an ideal location for UHS, with the rich exploration history of the area providing a readily accessible dataset to assess reservoir injectivity, seal containment and hydrogen storage capacity.The investigation showed that the fields in the Port Campbell Embayment are highly favourable for UHS. The Waarre Formation reservoir is capable of multiple cycles of injection and withdrawal, whileFigure 1.Calculated hydrogen storage capacities in the Port Campbell Embayment, Otway Basin.the Belfast Mudstone seal is capable of retaining column heights of hydrogentechnique to reduce geothermallogs and integration of previous ranging from 55 to 1267 m, which, withexploration risk on the Morningtonmodelling and studies has led to the the exception of a single measurement,Peninsula (ONeill etal., 2022a). production of new maps for temperature, exceeds the greatest known verticalgeothermal gradient, depth to top of closures in the onshore Otway Basin. The collation of historic geothermal dataaquifer, transmissivity and groundwater in the Gippsland Basin together withquality (ONeill etal., 2022b). The study The hydrogen storage capacity ofacquisition of new precision temperatureidentifies the Lower Tertiary Aquifer each field was calculated and ranked (Figure 1), with the total working gas capacity for hydrogen storage in the Port Campbell Embayment assessed to be approximately 120 Bcf (43 PJ) (Eid & Goldie Divko, 2022).Investigating geothermal energy prospectivity in VictoriaTwo recently published reports one focussed on the Mornington Peninsula and the other on the Gippsland Basin, present data and tools for assessing geothermal energy potential in Victoria.A combination of passive seismic data collected at ten locations and regional ground gravity data were used to model the depth of target stratigraphy hosting a geothermal aquifer (Figure 2). This modelling led to the development of a vertical profile of subsurface stratigraphy, including the top of the geothermal aquifer and the thickness of the overlying insulating sedimentary sequence along the Mornington Peninsula, south of Melbourne. Using horizontal to vertical spectral ratio (HVSR), passive seismic results to constrain regional gravity modelling may provide a cost-effectiveFigure 2.Passive seismic station locations on the Mornington Peninsula. Background is Bouguer gravity.35 PREVIEW FEBRUARY 2023'