Hydrogen in Australian natural gas: occurrences, sources and resources

Abstract

Natural or native molecular hydrogen (H2) can be a major component in natural gas, and yet its role in the global energy sector’s usage as a clean energy carrier is not normally considered. Here, we update the scarce reporting of hydrogen in Australian natural gas with new compositional and isotopic analyses of H2 undertaken at Geoscience Australia. The dataset involves ~1000 natural gas samples from 470 wells in both sedimentary and non-sedimentary basins with reservoir rocks ranging in age from the Neoarchean to Cenozoic. Pathways to H2 formation can involve either organic matter intermediates and its association with biogenic natural gas or chemical synthesis and its presence in abiogenic natural gas. The latter reaction pathway generally leads to H2-rich (>10mol% H2) gas in non-sedimentary rocks. Abiogenic H2 petroleum systems are described within concepts of source–migration–reservoir–seal but exploration approaches are different to biogenic natural gas. Rates of abiogenic H2 generation are governed by the availability of specific rock types and different mineral catalysts, and through chemical reactions and radiolysis of accessible water. Hydrogen can be differently trapped compared to hydrocarbon gases; for example, pore space can be created in fractured basement during abiogenic reactions, and clay minerals and evaporites can act as effective adsorbents, traps and seals. Underground storage of H2 within evaporites (specifically halite) and in depleted petroleum reservoirs will also have a role to play in the commercial exploitation of H2. Estimated H2 production rates mainly from water radiolysis in mafic–ultramafic and granitic rocks and serpentinisation of ultramafic–mafic rocks gives a H2 inferred resource potential between ~1.6 and ~58MMm3 year−1 for onshore Australia down to a depth of 1km. The prediction and subsequent identification of subsurface H2 that can be exploited remains enigmatic and awaits robust exploration guidelines and targeted drilling for proof of concept.

Native H2 Exploration in the Western Pyrenean Foothills

“…The discovery of these hotspots paves the way for detailed studies of noble gas and stable isotopes compositions, but also for careful microbiological and pedological investigations to better constrain H 2 source(s) and migration path. The targeting approach deployed in our study may be applied elsewhere in the world (e.g., Boreham et al., 2021) and more particularly in orogenic belts presenting a geological configuration comparable to the western Pyrenean area. These orogenic areas, rich in ultramafic rocks, could be preferentially targeted for an industrial prospection of native H 2 resources.…”

Can Weathering of Banded Iron Formations Generate Natural Hydrogen? Evidence from Australia, Brazil and South Africa

“…The latter is mined in BIF-hosted iron ores, mainly in Western Australia, making Australia the first iron ore producer worldwide. The presence of H2 in wells have been noticed in Australia for almost one century [31,32]. More recently, numerous SCD have been noticed in Western and Central Australia, probably indicating H2 seepage [12,26].…”

“…These rocks are essentially detrital. Nowadays, iron is largely exploited in South Africa, where Fe-rich lithologies are The presence of H 2 in wells have been noticed in Australia for almost one century [31,32]. More recently, numerous SCD have been noticed in Western and Central Australia, probably indicating H 2 seepage [12,26].…”

Evaluating Australia’s energy commodity resources potential for a net-zero emission future

“…Hydrogen production will be a major contributor to the decarbonisation of energy, transport and manufacturing industries. Hydrogen from geological sources (geologic hydrogen) has been found in Australian natural gas samples (Boreham et al 2021), gaining an increasing share of exploration investment and activity globally. If found in commercially exploitable quantities, geologic hydrogen could potentially support the transition to a low-carbon economy.…”

“…If found in commercially exploitable quantities, geologic hydrogen could potentially support the transition to a low-carbon economy. The origins of geologic hydrogen are varied (Boreham et al 2021) and is found in shallow reservoirs encompassing igneous, metamorphic and sedimentary rocks. It is also thought to be a prominent component of the lower mantle-core.…”