LONDON Oct 30 (Reuters) - Leading figures from the Middle East oil industry added their voices on Tuesday to those warning that the world is struggling to sustain rising oil production.
"There is a real problem -- that supply may not be possible to increase beyond a certain level, say around 100 million barrels," Libya's National Oil Corporation chairman Shokri Ghanem said at an industry conference.
"The reason is, in some countries production is going down and we are not discovering any more of those huge oil wells that we used to discover in the Sixties or the Fifties."
Sadad al-Husseini was a key architect of Saudi Arabian energy production policy for more than a decade whilst a top official at state oil firm Saudi Aramco. He was even more pessimistic, saying world oil production had already plateaued.
"We are already three years into level production," Husseini also told the annual Oil & Money conference, a gathering of top executives.
The views are far more conservative than those of the International Energy Agency, adviser to consumer countries, that supply will rise to 116 million bpd by 2030 to meet demand, from about 86 million bpd now.
Production is in decline in some regions, such as the North Sea, increasing the burden on other producers such as the 12 members of the Organization of the Petroleum Exporting Countries.
A five-year rally in oil prices, which hit a record high above $93 a barrel on Monday, is leading to growing interest in peak oil -- the view that supply has reached, or will soon reach a high point and then fall.
"So many people are talking about the peak oil theory," Ghanem said. "It is not the figure itself but the principle that the world cannot continue being able to produce oil infinitely."
Peak oil theory has its detractors, who say technology can help extend the life of the world's reserves.
The price surge has also coincided with rising scepticism about the size of the world's oil reserves.
OPEC sits on about 75 percent of the world's total proven oil reserves of 1.208 trillion barrels, according to figures compiled by BP in its Statistical Review of World Energy.
Husseini said at the conference that reserves estimates are too high and oil prices can only remain on a rising trend.
Proven oil "reserves" are overstated by 300 billion barrels of speculative "resources", mainly in OPEC countries, he said. By 2030, production of oil and natural gas liquids could fall to about 75 million bpd.
"As long as demand continues to grow, oil prices can only go up," said Husseini.