Saudi Arabia is sure its 35,000-strong security force can protect its oil installations from the rising threat of terrorist attack in the region, the former chief of Saudi intelligence services said.

A wave of unrest rippling across the Arab world this year has uprooted governments and laid fertile ground for terrorist groups, Saudi Prince Turki Al-Faisal said in a speech at the Royal Elcano Institute in Madrid.

But the world's top oil exporter remains confident the billions spent on protecting its biggest export earner will still shield its energy infrastructure from any attack.

"With governance in Yemen, Libya, Tunis, Egypt, Syria and other nations in such tenuous states, the perfect conditions for terrorist cells to take root and conduct desperate, evil and anarchical acts are created," he said.

"While the general picture of Saudi Arabia's surroundings is predominated by this great turmoil, at the centre of these many storms sits our Kingdom, which, I am glad to report, remains stable and secure," he said in a speech sent to journalists.

"I am also glad to report that Saudi Arabia's oil producing infrastructure has proven, and will continue to prove, immune to attack."     

Saudi Arabia -- which is thought to keep some "redundancy" in its oil export system as insurance against some facilities being disabled -- created a large industrial security force in 2006 after a failed al Qaeda attack on the world's largest oil processing plant at Abqaiq.    

In 2009, around 85 percent of revenues were from oil and a surge in oil prices in 2011 should boost Saudi oil earnings to $300 billion this year and average around $250 billion per year for the next five years, Prince Turki said.

Massive spending packages announced earlier this year have so far helped avoid widespread social discontent but have increased the kingdom's oil revenue needs, analysts say. - Reuters