Exploring for the Future: Molecular and Isotopic Compositions of Natural Gases from Nangwarry 1, Onshore Otway Basin, South Australia

<div>Exploring for the Future (EFTF) is a program dedicated to exploring Australia’s resource potential and boosting investment. This program is designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of onshore basins and attract exploration investment to Australia. This record presents geochemical analyses of natural gases sampled from Nangwarry 1, located in the onshore Otway Basin, undertaken in partnership with the Department for Energy and Mining – Energy Resources, Government of South Australia, as part of the EFTF program Natural Hydrogen module. The Nangwarry Joint Venture drilled Nangwarry 1 to investigate the potential for the development of food grade, carbon dioxide production from this well. The results of the molecular and stable carbon and hydrogen isotopic analyses undertaken by Geoscience Australia are released in this report. The molecular data show that the gas composition in this well has an average of 96 mol% CO2 with an isotopic signature indicative of a magmatic origin, being comparable with previously produced gases from onshore Otway Basin wells (e.g. Boggy Creek 1, Caroline 1) for use by the food industry. The carbon and hydrogen isotopic composition of the C1–C5 hydrocarbon gases from Nangwarry 1 are suggestive of a source from within the Crayfish Supersequence.</div>