Italian oil giant Eni is moving forward with plans to tap into massive oil sands deposits in the Republic of Congo.

"We have put in place a small pilot which will start next year," Eni Chief Executive Paolo Scaroni reportedly said after meeting recently with Congolese president Denis Sassou N'Guesso.

The company estimates total recoverable reserves could be as high as 2.5 billion barrels. Eni has been eyeing the central African nation ever since it signed an exploration and development agreement with the government of Congo in 2008, pledging to invest $3 billion over four years.

The oil major has stated extraction won't harm fragile tropical rainforest or force locals to resettle.

"All this will be done, taking into account the environment, which is the number one priority of our activity in Congo," Scaroni said.

Yet more than two-thirds of the company's exploration zone is covered by forest or other bio-diverse areas, internal documents reveal.

Eni hasn't stated what type of extraction method it will be using, leaving observers to speculate that deep deposits may be tapped with in-situ steam injection technology.

"Given the high risk of irreversible environmental and social damage, [Eni should] cancel the investments in tar sands for oil production," reads a 2009 report from the Heinrich Boll Foundation, the German Green Party's think tank.

Canada is currently the only country with large-scale production of oil sands crude. But The Tyee reported last year how success in Alberta is encouraging major energy players to develop unconventional oil deposits across the world.

Geoff Dembicki reports on energy and climate issues for The Tyee.