Saudi Arabia's official statement suggests that the shutdown may take longer

Citigroup said Saudi official statements suggested that the shutdown could take longer than expected, "maybe a few months"; production may not fully recover by the end of the year, with a loss of 1 million to 2.5 million barrels per day expected.

Beijing time, Sept. 17, Saudi Arabia's oil industry center was hit by an attack that forced the country to cut its oil production by half, intensifying market concerns about supply. Crude oil futures prices soared sharply on Monday, with U.S. oil rising by the largest one-day rate in more than 11 and a half years. West Texas Light Crude Oil (WTI) futures, delivered on the New York Mercantile Exchange in October, surged $8.05 to close at $62.90 a barrel, up 14.7%, setting a high close on spot contracts since May 21. According to data provided by FactSet, a financial information provider, this means that WTI futures have registered the largest one-day percentage increase since September 22, 2008, based on the main contract. At the same time, Brent crude oil futures for November delivery on the London ICE European Futures Exchange also surged $8.80 to close at $69.02 a barrel, up 14.6%, the largest one-day increase ever recorded in percentage terms, and the largest one-day increase since June 2008 in dollar terms. The biggest one-day increase since 6 days.