According to banker Matthew Simmons, "Saudi secrecy and reports describing intensifying efforts to recover oil suggests that production may already have peaked."

"The Saudis - and other OPEC members - [have] to publish field-by-field data on oil reserves and production. [Besides,] water injected into Saudi reservoirs to maintain pressure might curtail the life of several fields and render unrecoverable as much as three-fourths of the oil in place," he warned.

"Everyone's 'plug' factor for future energy growth is Saudi Arabia's ability to increase its oil flow. If this premise is wrong, the world is in for a nasty shock," added Simmons, echoing many US analysts who do not believe that Saudi Arabia cannot meet future demand.

To these allegations, Saudi Aramco reservoir manager Nansen Saleri says 'watch us'. According to Nansen, "[Saudi Aramco] could raise production by 50% to 90% and sustain those levels for more than 50 years. The water content of oil production at the kingdom's largest and most mature oil field [is] 36%; lower than many other producing fields in the world."

"Saudi Aramco, with advanced engineering and conservative management, expects to recover as much as 75% of the oil in its giant fields. These are very achievable. We don't see this as a major challenge," added Nansen.

The good doctor's estimation is echoed by the company's vice president for exploration, Mahmoud Abdul Baqi. "The company could readily finance capacity expansion to 12 million or 15 million barrels a day over the next decade," said Mahmoud.

Saudi Arabia is the world's largest exporters of oil and claim proven reserves of around 264 billion barrels. Its current capacity is around 10 million barrels per day.