Singapore: Saudi state oil firm Aramco's long-term sustainable oil output level will be 10.4 million barrels per day after 2010, far below its maximum capacity of 12 million bpd, the BusinessWeek magazine reported.

Saudi Arabia has said it will pump 9.7 million bpd this month, its highest rate in over three decades and 550,000 bpd more than in May, and has pledged to keep pumping at that level for the rest of the year if customers demand the extra oil.

Saudi Arabia, the world's biggest exporter, is on track to boost output capacity to 12.5 million bpd by the end of next year. Saudi Aramco will hold 12 million bpd of that total.

The kingdom has said it is ready to take total capacity to 15 million bpd in coming years in a bid to tame roaring prices fuelled in part by growing fears over limited global supplies.

But BusinessWeek, citing a field-by-field breakdown of output it obtained from an oil industry executive, said that Aramco would be unable to pump at 12 million bpd for long.

Counter claims

"The detailed document... suggests that Saudi Aramco will be able to maintain that volume only for short, temporary periods such as emergencies," BusinessWeek reported in an online article dated July 10.

"Then it will scale back to a sustainable production level of about 10.4 million barrels a day."

Speculation over Saudi Arabia's ability to increase output, and to keep it at higher levels, has grown in recent years as the kingdom's mammoth decades-old fields begin to age, although the Saudis maintain they have plenty of crude in the ground.

Last month, senior Aramco executive Ameen Al Nasser said that the kingdom could pump at 15 million bpd for at least 30 years. Saudi Arabia would only bring on any increment in capacity provided it could last for that long, he added.

The world's largest oilfield is in Saudi Arabia at Ghawar. That field would see output of around 5.4 million bpd next year fall to around 4.475 million bpd in 2013, BusinessWeek said.

Aramco's Nasser said last month that Ghawar would pump at around five million bpd for "many, many years to come."

The kingdom has a long-held policy to maintain idle capacity of around 1.5-2.0 million bpd to ensure it can quickly meet any emergency shortages in the global market, capacity that is not necessarily intended to be used on a long-term basis.

Saudi Arabia's output capacity is around 500,000 bpd higher than Aramco's capacity, as output from the Neutral Zone shared with Kuwait is not included in calculations for Aramco.