Known accumulations of naturally occurring hydrogen and helium exist within the Amadeus Basin.
Process
Naturally occurring hydrogen and helium are both non-hydrocarbon gases. Similar to conventional oil and gas, accumulations of these non-hydrocarbon gases may be found in geological traps within a porous and permeable reservoir.
Both hydrogen and helium can be a component of natural gas along with hydrocarbons and other non-hydrocarbon gasses such as carbon dioxide, hydrogen sulphide and nitrogen. However, there are examples globally and in Australia where these gasses are trapped without associated hydrocarbon-rich natural gas.
Unlike other natural gas components, naturally occurring hydrogen and helium are not generated from the breakdown of organic material over geological time. Hydrogen is commonly produced from water radiolysis of igneous rocks or through serpentinisation of ultramafic rocks. Helium is commonly produced by the decay of radiogenic material sourced from granitic rocks in the Earth’s crust. These rocks are commonly most abundant in Proterozoic granitic rocks and are subsequently transported into sedimentary basins through groundwater interactions.
High levels of naturally occurring hydrogen and helium have been recorded from the Amadeus Basin in Neoproterozoic sub-salt plays within the basal Heavitree Formation and fractured basement. The hydrogen and helium is associated with hydrocarbons and is sealed by a thick salt layer of the Gillen Formation. The Mt Kitty-1 well, drilled in 2014 in the southeastern Amadeus Basin, encountered approximately 9% He and 11.4% H2, whereas the Magee-1 well (drilled in 1992) encountered 6.24% He and 0,03% H2 (Leila et al 2022). Central Petroleum and Santos targeting helium in the southern Amadeus Basin.
The McArthur Basin may be prospective for hydrogen and helium but exploration is limited. The Georgina and Ngalia basins are analogous to the Amadeus Basin and make up some of the prospective frontier basins that remain largely underexplored by world standards.
Australia’s only helium extraction plant, based in Darwin, closed in late 2023 with the depletion of the helium rich Bayu-Undan field. Other sources to support the helium plant are being investigated.
Links to more information
Leila, M, Loiseau K and Moretti I, 2022. Controls on generation and accumulation of blended gases (CH4/H2/He) in the Neoproterozoic Amadeus Basin, Australia. Marine and Petroleum Geology 140, 105643
View the distribution of petroleum wells and seismic lines and download attributed spatial data across the Territory’s onshore basins through the Northern Territory Geological Survey's (NTGS) online web mapping system STRIKE .
