Junin 6 'has proved reserves of some 10 billion barrels of petroleum, which will allow for production of some 400,000 barrels per day for 25 years until a recovery rate of 20 percent is achieved,' the official ABN news agency reported.

The Orinoco Belt, located in east-central Venezuela, is believed to hold the world's largest petroleum reserves, with most of the oil heavy and extra-heavy crude that is more expensive to refine because it requires additional processing.

Venezuela has been working with foreign oil companies - both private and state-owned - to certify its reserves, which have been estimated at 314 billion barrels, making them the world's largest petroleum reserves.

The South American nation is the world's fifth-largest oil exporter.