Soil gas surveys for hydrogen and helium in New South Wales

Exploring for the Future (2016-2024) was an Australian Government program led by Geoscience Australia (GA), in partnership with state and Northern Territory governments. The program aim was to drive industry investment in resource exploration in frontier regions of Australia by providing new precompetitive data and information about energy, mineral and groundwater resource potential. 

To address this overarching objective, GA led a key element of the Australian Government’s commitment to achieve net zero by 2050. The energy transition to an ever decreasing carbon emission economy will involve the increasing use of hydrogen gas (hydrogen). The key benefit of using hydrogen is that it is a clean fuel, emitting only water vapour and heat when combusted. However, hydrogen today is manufactured at a relatively high cost. The recent discovery of a 98% per cent pure natural hydrogen field in Mali (Africa) has led to low cost hydrogen production. It has also captured the imagination of explorers and the search is now on for new natural hydrogen accumulations across the world. Australia is considered one of the most prospective locations for sub-surface natural hydrogen due to our ancient geology and potential presence of suitable hydrogen traps. A review of occurrences of hydrogen in natural sub-surface rocks found high concentrations of hydrogen in central western, New South Wales (NSW). Helium is extracted in commercial quantities from natural gas and Australia currently has no local production. This project, in collaboration with the Geological Survey of NSW (GSNSW), built on the desktop review and has identified new occurrences of natural hydrogen and helium through soil gas surveys in various locations across central and far west, NSW. 

To support the Exploring for the Future program, six soil gas surveys for natural hydrogen and helium were jointly undertaken by staff from GA and GSNSW across central and western NSW during 2022-23. The project also included sites near the Tumut township to test various soil gas sampling techniques as well as the major focus in the Curnamona Province and Delamerian Orogen in far west New South Wales. In the first phase of the project, conceptual geological models for natural hydrogen and helium generation and accumulation were developed using pre-existing geoscientific data, including electromagnetic, magnetotelluric, magnetic, gravity, radiometric, drilling, seismic and satellite-derived data. The selected sites represented various concepts for natural hydrogen and helium generation, such as granite rocks rich in potassium, thorium, and uranium, banded iron formations, ultramafic rocks, and diatremes. The second phase of the project was the collection of soil gases from shallow (1 m deep) installations and subsequent molecular and isotopic compositional analysis at the GA Laboratory. Maximum hydrogen and helium concentrations in the soil gases are 309.5 ppm and 35.3 ppm, respectively, which is comparable to and even exceeds previously reported soil gas surveys both in Western Australia and overseas. The final phase was the integration of all datasets within a GIS platform for the interpretation and presentation of maps within this report.

Tags: EARTH SCIENCES, EFTF – Exploring for the Future, Gas seepage, Helium, Natural hydrogen, Published_External, SIRF - Strategic Innovative Reserve Fund, Soil gas
Organization: Geoscience Australia Data