Naturally occurring hydrogen is increasingly becoming the focus of exploration activity around the world, with projects underway in South Australia, the US and France.

Naturally occurring hydrogen, also referred to as geologic hydrogen, gold hydrogen and white hydrogen, is created when water is split underground following reactions with iron-rich rocks.

A recent discovery in the Lorraine Mining Basin in France by French company FDE found 98% pure hydrogen at a depth of 3,000m. FDE has applied for an exclusive exploration permit covering an area of 2,254 km² in the Grand Est region.

It is the first significant find of natural hydrogen in Europe, although other regions have been focusing on the resource for some time.

There is only one producing field in Mali, West Africa. A pilot project run by production company Petroma—now called Hydroma—has supplied the village of Bourakebougou with power generated from the field for seven years.

An academic study conducted in 2018, titled Discovery of a large accumulation of natural hydrogen in Bourakebougou (Mali), found an extensive hydrogen field at least 8km in diameter in the area. The study also found the field has seen no depletion to date, suggesting it could be naturally regenerating.

Licence to drill

The South Australian state government, the first place to grant exploration licences for natural hydrogen, has received 40 applications for such licences.

$1/kg – Price Gold Hydrogen believes it can produce the fuel

One of these licences was awarded to natural gas extraction firm Gold Hydrogen, which recently reported that soil gas testing around its Ramsay Project in South Australia, conducted by The Commonwealth Scientific and Industrial Research Organisation, found hydrogen in multiple locations. The firm has plans to drill two wells for natural hydrogen in the area in mid-October.

On a podcast with price reporting agency ICIS, Gold Hydrogen managing director Neil McDonald said he believed the firm could produce the hydrogen for less than $1/kg.

US firm HyTerra, which has conducted an initial test on a well in the US state of Nebraska, is also targeting $1/kg of production costs. The firm’s tests were interrupted in April due to a mechanical failure with the pump.

Estimated reserves

One of the big questions around natural hydrogen is the size of the global resource and how much demand it might meet. Uncertainties associated with the generation, migration, accumulation and preservation of hydrogen in the subsurface make it difficult to precisely determine potential resource volumes.

The high volume of seepages detected all around the planet suggest great potential but could indicate that hydrogen molecules are easily escaping rock formations, according to Dariusz Strapoc, senior geochemist at oilfield services company SLB, speaking on a recent webinar organised by the Society of Petroleum Engineers.

“We see hydrogen seepages all over the planet,” he said. “The question is whether those seepages are economic or obtain high enough flow rates to make this a part of the solution for a decarbonised future.”

Stochastic modelling carried out by US Geological Survey research geologists Geoffrey Ellis and Sarah Gelman came up with a range of numbers for potential natural hydrogen reserves, with some as high as 1tn t, although the geologists have been careful to note that much of this hydrogen was likely to be inaccessible.

However, only a fraction of these reserves would need to be explored to provide a supply rivalling that of green and blue hydrogen deployment forecasts.

Gold Hydrogen’s McDonald believes there will be adequate accessible deposits once firms start to explore for the resource.

“Geologically, you will find there will be more deposits around the world; it is just that no one has looked for it previously,” he said.

Hydrogen could theoretically be tapped using small modifications to drilling and completion equipment used for natural gas development, although there are uncertainties about how the molecule would behave during drilling.

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Author: Tom Young