An Aramco employee walks near an oil tank at Saudi Aramco's Ras Tanura oil refinery and oil terminal in Saudi Arabia. Ahmed Jadallah | Reuters

Oil rose on Wednesday, touching a fresh four-year high as the market focused on upcoming U.S. sanctions on Iran and shrugged off a surprisingly big build in U.S. crude stockpiles and reports of higher Saudi Arabian and Russian production. "Nothing matters between here and Nov. 4," said Bob Yawger, director of futures at Mizuho in New York, referring to the date when U.S. sanctions take full effect. U.S. crude inventories jumped 8 million barrels last week, quadruple analysts' expectations and the biggest build since March 2017, the Energy Information Administration said on Wednesday. Both crude benchmarks briefly moved lower on the EIA report before reversing course.

"The speculative community took an opportunity to buy on the dip," Yawger said. Global benchmark Brent crude settled up $1.49, to 1.8 percent, to $86.29, it best closing price since October 2014. U.S. West Texas Intermediate (WTI) crude futures ended Tuesday's session up $1.18, or 1.6 percent, at $76.41 a barrel, the highest closing price since November 21, 2014. Earlier in the session, crude had been pushed lower as Saudi Energy Minister Khalid al-Falih said the kingdom had raised output to 10.7 million barrels per day in October and would pump more in November. The record high for Saudi output is 10.72 million bpd in November 2016. Russia and Saudi Arabia struck a private deal in September to raise oil output to cool rising prices and informed the United States before a meeting in Algiers with other producers, four sources familiar with the plan told Reuters. Al-Falih, who is attending a Moscow energy conference with Russian President Vladimir Putin and other influential energy officials, said Saudi Arabia has successfully met additional demand. "We see the market is being well supplied," he said.