Saudi Aramco is in emergency talks with contractors as it attempts a quick recovery from missile attacks on its oil-processing facilities, The Wall Street Journal reported, and as it looks to stay on track with its forthcoming blockbuster initial public offering.

Global oil prices last Monday posted their biggest surge in nearly two decades after a weekend drone attack on two Saudi Arabian crude facilities inflicted substantial damage on the country's oil-production operations, threatening global supply in the process.

Citing both Saudi officials and oil contractors, the Journal said it may take many months to restore operations to full working order, and that costs could run into the hundreds of millions of dollars.

Saudi Arabia has suggested Iran, which has also been implicated in drone attacks on various oil tankers in the Strait of Hormuz earlier this year, is behind the attacks, although rebels linked to the Yemeni Houthi have claimed responsibility. 

Separately, Bloomberg News reported that Saudi Aramco has added banks including Barclays, BNP Paribas, Deutsche Bank and UBS as bookrunners on its IPO.

The energy giant also picked Credit Agricole, Gulf International Bank and Societe Generale as it pushes ahead with plans for the blockbuster deal, Bloomberg reported, citing people with knowledge of the matter.

Aramco is planning to select about 15 bookrunners in total, including two Chinese firms, one of the people told Bloomberg.

Brent crude contracts for November delivery were down 0.66% at $64.34 per barrel in Monday New York trading.