By Reem Shamseddine

KHOBAR, Saudi Arabia (Reuters) - Oil giant Saudi Aramco is using new technology to re-explore areas of the vast Arabian desert known as the Empty Quarter, which could help to bolster its proven reserves of oil and gas before the company offers its shares to the public.

A team of about 900 people is using advanced seismic technology developed over the last few years to explore 15,400 square kilometers (5,950 square miles) around Turayqa in Saudi Arabia, Aramco said in a statement.

Turayqa, discovered in 2013, is an onshore conventional gas field that contains no oil. Part of the area was previously explored by joint ventures involving Aramco and foreign companies, Aramco said. The JVs failed to find recoverable quantities of oil and gas.

"Data processing is ongoing. The area partially covers areas relinquished by some of the joint ventures," the company told Reuters.

Aramco set up four consortia in 2003 and 2004 to explore the Empty Quarter, but they ended their search after failing to find commercial volumes of gas.

The new seismic technology may improve the chances of successful exploration, though it cannot by itself prove the existence of oil and gas reserves; drilling is needed for that.

Seismic technology uses artificially induced shockwaves in the earth. While conventional crews have 9,000 frequencies available to monitor the results, the crew at Turayqa has over 50,000.

"The seismic data acquisition technology that is being deployed is truly phenomenal," said a former executive at the company.

It not only provides a three-dimensional picture of the structure of rock going down several kilometers (miles), but also tells the user physical characteristics of the rock, such as its density and fluid saturation, he said.

"It is something that far exceeds what was achievable on land 10 years ago."

Industry analysts said it was not clear whether Aramco's new exploration efforts would affect the company's estimate of its oil and condensate reserves, which total 261 billion barrels and have been unchanged for many years.

Any change in the reserves could affect next year's planned international offer of a stake of roughly 5 percent in Aramco, since some investors' models are based on valuations of the reserves. Private analysts have calculated the offer could value the whole company at around $1 trillion or more, though the government has predicted at least $2 trillion.

An industry source familiar with Aramco's operations said that at the very least, its exploration effort in the Empty Quarter and around the kingdom would help the company maintain its current reserves estimate for some time to come.

"At current production of 10 million barrels per day, and assuming reserves of 261 billion barrels, a discovery of 1.5 percent of the reserves replaces the reserves depleted in a year," he said.

(Editing by Andrew Torchia and Adrian Croft)