A Stratigraphic Reconstruction of Bulk Volatile Chemistry from Fluid Inclusions in: Birksgate 1

Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia (GA), in partnership with state and Northern Territory governments. The EFTF program (2016-2024) aims to drive industry investment in resource exploration in frontier regions of onshore Australia by providing new precompetitive data and information about their energy, mineral and groundwater resource potential. Under the EFTF program, the Onshore Energy Project undertook a study of petroleum prospectivity of the onshore Officer Basin in South Australia and Western Australia. Birksgate 1 well in South Australia was selected based on the occurrence of gas and oil shows reported in the well completion report. Sampling of cuttings and cores was done at Geoscience Australia's Petroleum Data Repository in Canberra. Geoscience Australia commissioned a fluid inclusion stratigraphy (FIS) study on the downhole samples. Here, volatile components ostensibly trapped with fluid inclusions are released and analysed revealing the level of exposure of the well section to migrating fluids. Integration of thin section (TS) preparations reveal to extent of gas and fluid trapping within fluid inclusions while microthemometry (MT) gives an estimation of fluid inclusion trapping temperature. For Birksgate 1, FIS analysis was performed on 414 cuttings and 33 cores between 150 feet and 6161 feet base depth, together with 14 samples prepared for TS and 3 samples for MT. To support this study, lithostratigraphic tops were compiled by Geoscience Australia. The results of the study are found in the accompanying documents.