A Wealth-X survey released in January put his fortune at $14.7bn - $2bn larger than that of Chelsea Football Club owner Roman Abramovich, and about $1bn ahead of Alisher Usmanov.

In 2004 Vekselberg, described last year by the Financial Times as a "Kremlin-friendly tycoon" spent slightly more than $100m buying nine Faberge eggs. He told the BBC the eggs gave him a "warm glow". But his specialty is exploration.

"Viktor's very managerial," says former junior minister Conor Lenihan, who worked with Vekselberg on the Skolkovo project - the continuing construction of a tech hub comparable to Silicon Valley outside Moscow.

"He's one of those entrepreneurs who has fantastic managerial skills and works well with his team. He drives his team extremely hard.

"Like any other rational investor, he is just looking for a return on his investment. The investment managers he would appoint to an investment like this would be very highly incentivised in relation to getting a return."

So what has him involved with Falcon? Renova's Moscow spokesman didn't comment on the specific reasons when contacted by the Sunday Independent, but Falcon's high-potential portfolio probably holds the key.

The company's flagship asset is a 30pc interest in the 4.6m-acre Beetaloo basin in northern Australia. Shortly it will break ground on the first of three exploration wells due to be drilled as part of a $200m farm-out deal with Sasol and Origin, which included a $20m cash payment up front. The Beetaloo is seen in the industry as a major litmus test which will reveal much about the viability of fracking outside the USA.

Falcon won't have to a pay a penny towards the cost of the first three wells, which are designed to see if the basin is commercially viable. Next year the plan is to start fracking - drilling into the ground and shooting rocks with a high-pressure mixture of water, sand and chemicals to release the resources inside.

The Dublin-based fracker - probably the most interesting Irish-listed company of which you've never heard - is run by Philip O'Quigley, the former chief financial officer of Tony O'Reilly's Providence Resources. Chairman is John Craven, the former chief executive of Cove Energy which was sold for £1.2bn. Craven was the founder of Petroceltic and the man who floated it.

Maxim Mayorets, Vekselberg's head of mergers and acquisitions - or top dealmaker in plain English - is on Falcon's board. So is Gyorgy Szabo, a Hungarian who oversaw the extinguishing of some of the Kuwait oil fires in the early 1990s.

O'Quigley looks to have left Providence at the right time. Dublin, London and Toronto-listed Falcon is valued at €138m, nearly four times as much as Providence, with O'Reilly's company dropping precipitously in value over the last year.

Carlow native O'Quigley (52) trained as an accountant with Ernst & Young and later became financial director at Craven's Petroceltic. Then he was CFO of Providence from 2008 until he became Falcon boss in 2012. He remains on Providence's board as a non-executive director. He joined Falcon after an approach from Craven.

"Falcon was not in a good place at that time with debt on the balance sheet and the prospect of running out of cash being just two of its many challenges. But given the quality and scale of Falcon's assets, this was an opportunity too good to miss. The dynamics of running a junior oil and gas company are vast - but my four years at Providence proved to have been a great training ground for my role as CEO of Falcon as I learnt so much from working with Tony O'Reilly.

"It's an industry full of great characters and an industry that quickly grows on you like no other. The risks of failure are huge but so too are the rewards of success and it is the constant uncertainty of not knowing which is around the corner that is the thrill... the scale, the technical challenges and advances and the fact energy remains the cornerstone of economic prosperity makes it a very rewarding industry."

It's also an industry that's very different from the norm. Falcon has a market capitalisation of €138m, even though it's not producing anything. The value is based entirely on the potential of its portfolio, which may never be realised.

As O'Quigley puts it: "Falcon cannot be a small success. It will either not work at all, or be a success on a huge scale."

The Falcon boss drives a hard bargain. In 2013 he refused to give US oil giant Hess an extension on a drilling commitment in the Australian asset - effectively kicking them out the door.

"They had an activist investor on the register which was putting great pressure on them to retrench their overseas investment so they tried to buy another time extension with the wrong man," O'Quigley said. "It was a very tough decision, but the terms of the deal we did with Origin and Sasol are far better."

Fracking is controversial - opponents say there are risks of groundwater contamination. Daniel Schrag, a Harvard academic and advisor to US President Barack Obama, said there are environmental risks but that they aren't "that much worse than conventional gas."

The UK Royal Society and Royal Academy of Engineering said "the health, safety and environmental risks associated with hydraulic fracturing as a means to extract shale gas can be managed effectively in the UK as long as operational best practices are implemented and enforced through regulation."

O'Quigley says only that "debate is good and it is right to have a debate on this issue. But the debate needs to focus more on the facts and less on the myths."

Falcon's second most valuable asset is in the Karoo basin in South Africa. Its partner there is US giant Chevron. That country is suffering from a massive energy shortage and successful gas development there would be huge for Falcon. The Energy Information Administration ranks the Karoo in the top five unconventional basins in the world.

Despite the fall in oil Falcon's share price is about the same as a year ago. Davy analyst Job Langbroek has an 'outperform' rating on the stock.

"Shale gas and light tight oil and all that has been a game-changer in the industry and has really survived initial scepticism by everybody really," Langbroek told the Sunday Independent.

"Its genesis was in the US and in many ways the US is the perfect test tube. It's got the right rocks, it had the infrastructure, or most of it. It had a legislature that was friendly towards oil and gas, the local landowners get recompensed. The big question is, is it repeatable elsewhere?

"I think the answer is probably out that it's very hard to repeat it in Europe. Let's leave the UK aside for a moment as the jury's out on that. Other places where you might get it, think China, think Argentina, think Australia and South Africa. Those places have the right rocks. They probably have the right attitude to them, in the sense that either they can get it done or there's not an awful lot of people around. There are questions about markets. Where does the gas go? Are there enough companies? Is there enough service infrastructure? But a lot of those boxes are ticked by Australia - the gas can go north to Asia, they've got plenty of water, and they seem to have a friendly enough legislature.

"The model that he follows is you use shareholder funds to set up the asset play at the start, and then you do it in such a way that you've used your local knowledge and skill to set yourself up so you develop an asset that the industry wants to get involved in. And he's done that in Australia.

"It's a good deal in the sense that he's no capital upfront, it's a big uplift on the carried valuation prior to that, and when the wells get drilled and if they've discovered gas and if it becomes a viable project, then you get another value uplift.

"There's no easy comparable Irish-listed company doing unconventionals. It really puts them in another category."

http://www.independent.ie/business/irish/russias-richest-oligarch-backs-irish-fracking-firm-falcon-oil-in-gamble-31335012.html