At the same time, some of the biggest oil companies are investing less than before the 2008 oil price crash even though economic recovery is forecast to drive global demand to unprecedented levels.

OPEC Secretary-General Abdullah Al-Badri said this week the 12-member group would spend $155 billion on projects coming on stream between 2010 and 2014, which would add 12 million barrels per day (bpd) of gross production capacity.

But much of that is likely to go into maintaining output at existing fields rather than developing new ones. Top exporter Saudi Arabia spends billions each year to hold capacity where it is, said Paul Tossetti, senior energy adviser at PFC Energy.

“When you look at the Saudis, they’ve basically finished their incremental oil capacity increases,” he said. “I don’t see much in the way of OPEC capacity increases in the next few years, aside from Iraq.”

Among the world’s three largest fully publicly traded oil companies, Royal Dutch Shell and BP Plc are raising their spending this year but not to the levels the companies were spending before the 2008 crash.

Exxon Mobil stands apart in that it increased its outlay through the downturn, although it has yet to announce investment plans for this year.

Shell said its cautious approach was based on a long-term view and sought to avoid the boom and bust of previous economic swings, when waves of new oil sent the price crashing. “We aim to keep our investment levels relatively constant through the business cycle,” said Simon Henry, Shell’s chief financial officer, at a post-results news conference this week.

“One of the ways of losing money in this industry is to follow the cycle too much and invest more as the prices go up.”

While the oil majors’ focus is relatively short-term, members of the Organization of the Petroleum Exporting Countries are concerned with maximizing oil revenues over the long term.

The influence of Saudi Arabia, in particular, derives from maintaining spare capacity that can be added or taken away from the market depending on the balance of supply and demand.

As he announced OPEC’s plans, Badri stressed the need for a customer base when deciding whether to increase capacity.

“If upstream investments are pursued without a careful consideration of global market conditions, the result could be a higher risk of idle spare capacity — and unnecessary costs to maintain this,” he told a London conference on Monday.

To illustrate demand uncertainty, Badri cited OPEC’s varying scenarios. In the more bullish, consumption rises by around 44 million bpd to 2030, while its lower-growth scenario pegs demand for OPEC oil at 28 million bpd — less than it produces now.

Badri did not specify whether the spending plan represented an increase, but the figures imply a rise from an outlook on OPEC’s website, which shows it spending more than $110 billion from 2009 to 2013.

A lag between supply and demand is inevitable, executives say, as it can take five to 10 years to bring on projects.

But even with unavoidable delay, rising demand and oil prices above $100 a barrel, officials inside and outside OPEC say there is no need for panic.

Nervousness about unrest in the Middle East aside, there is enough oil and no supply disruption yet.

Shell Chief Executive Peter Voser estimated OPEC’s spare capacity was around 5 million bpd — more than the 2 million bpd it held in 2008 when oil hit a record above $147 a barrel.

“In the absence of geopolitical factors, this may well cushion the markets from a spike in 2011,” Voser said.

Shell’s working assumption in assessing new projects, he said, was an oil price of $50-$90 a barrel.

That compares with Saudi Arabia’s oft-stated ideal of $70-$80. Anything less, producer countries have argued, would be counter-productive.

“OPEC gets mixed signals from OECD consumers, who want to reduce dependence on OPEC and introduce costly alternatives but also reduce oil prices, which can only increase demand and undermine alternatives,” said Sadad Al-Husseini, an oil analyst and former top official at Saudi Aramco. “Supply shortfalls can only get worse with low prices.”

In support for that argument, retrenchment was an immediate response to the market crash of 2008, when prices fell from their record high in July to just above $30 in December, and the impact was compounded by a credit crunch.

Small firms were forced to cut back the most drastically.

OPEC also scaled back. In February 2009, Badri said that of 150 projects scheduled to come online in the next few years, 35 had been deferred to after 2013.

The one hugely rich oil province in a cycle all of its own is Iraq, emerging from years of war and sanctions and with the potential to transform the supply-demand landscape.

The OPEC member has signed contracts with international oil firms to increase its capacity to 12 million bpd.

Analysts and politicians have since questioned how realistic that level is, although its oil minister said Iraqi production has already risen over 2.6 million bpd for the first time in 20 years.