Price of Brent crude could rally above $75 per barrel if oil outage in Saudi Arabia would last more than six weeks, Goldman Sachs said in a report.
"This is nonetheless a historically large disruption on critical oil infrastructure," the global investment banking firm warned late Sunday.
"These events represent a sharp escalation in threats to global supply with risks of further attacks," it added.
The kingdom's national oil company Saudi Aramco's two facilities were attacked by drones on Saturday, causing a supply disruption of 5.7 million barrels per day (mbpd).
While this amount is more than half of the country's total 9.7 mbpd oil production, it also represents close to 6% of global oil supply.
Goldman Sachs said the extent of the price rally is hard to estimate without further information from Saudi Arabia about "the timeline and scale of production losses."
Saudi officials later said 2 mbpd of disrupted oil production is expected to be restored as early as Monday.
"Should the disruption last a couple days, the impact on inventories and timespreads would be negligible," Goldman Sachs said.
By Ovunc Kutlu