- Brent crude prices rose on Thursday after Saudi Arabia suspended its oil shipments through a key Red Sea strait.
- The closure came in response to an attack on two of its tankers by the Houthi movement, which has been fighting a Saudi-led coalition for more than three years.
- Oil prices also got a boost from data on Wednesday that showed U.S. inventories fell to a 3½ year low.
Oil prices rose for the third consecutive day on Thursday after Saudi Arabia suspended oil shipments through a strait in the Red Sea after an attack on two oil tankers and as trade tensions between the United States and the European Union eased.
U.S. West Texas Intermediate crude futures ended Thursday's session up 31 cents, or half a percent, at $69.61 a barrel. Brent crude futures rose 73 cents, or 1 percent, to $74.66 a barrel by 2:28 p.m. ET.
After meeting European Commission President Jean-Claude Juncker at the White House on Wednesday, U.S. President Donald Trump agreed to refrain from imposing car tariffs while the European Union and the United States start talks on cutting other trade barriers.
"The market is very calm as it tries to assess the impact from the President Trump deal with the European Union to hold off on tariffs," said Phil Flynn, analyst at Price Futures Group in Chicago.
Brent rose in post-close trading on Wednesday after Saudi Arabia said it was "temporarily halting" oil shipments through the Red Sea shipping lane of Bab al-Mandeb after an attack by Yemen's Iran-aligned Houthi movement.
Saudi Arabia has a major export terminal in Ras Tanura — also home to the country's largest refinery — on its eastern coast. It exports most of its crude on tankers passing through the Strait of Hormuz.
From there, many ships have to pass through Bab al-Mandeb to get to the Suez Canal towards Europe and the SUMED pipeline in Egypt.
An estimated 4.8 million barrels per day of crude oil and refined petroleum products flowed through this waterway in 2016 toward Europe, the United States and Asia, according to the U.S. Energy Information Administration.
The Houthi forces that attacked that tankers are aligned with Saudi Arabia's regional rival Iran. Tensions in the region have increased since President Donald Trump restored sanctions on Iran, prompting its leaders to threaten to shut the Strait of Hormuz, the world's busiest sea lane for oil shipments.
"The Red Sea which was secure is no longer secure today with the presence of American forces," said Major-General Qassem Soleimani, who heads the Quds Force of Iran's powerful Revolutionary Guards Corps.
But Saudi Arabia additionally has the Petroline, also known as the East-West Pipeline, which mainly transports crude from fields clustered in the east to Yanbu for export. That could offset a bottleneck caused by Bab al-Mandeb's closure.
Olivier Jakob from Petromatrix said in a note it remains to be seen whether the Saudi move has an impact on insurance rates and the willingness of ship operators to use that channel.
"The passage is not as crucial as the Strait of Hormuz ... but restricted flows through it would have an impact not just for crude but also for products due to the longer voyage time that is needed to sail by the Cape," he said.
Prices were also supported by official data showing U.S. crude oil inventories last week tumbled more than expected to their lowest level since 2015 as exports jumped and stocks at the Cushing hub dropped.
Crude inventories fell 6.1 million barrels in the week to July 20, compared with analyst expectations for a decrease of 2.3 million barrels, the EIA said on Wednesday.
However, PVM strategist Tamas Varga said the draw was not as bullish as it may seem given most of it came from the west coast, which is separated from the rest of the country by the Rocky Mountains and therefore no clear indicator of a broader U.S. draw.
Still, at 404.9 million barrels, inventories, not including the nation's emergency petroleum reserve, were at their lowest level since February 2015.
Traders said Thursday that inventories at the U.S. storage hub in Cushing, Oklahoma, have continued to fall. They were forecast to drop by 1.1 million barrels through Tuesday, traders said, citing energy information provider Genscape.
— CNBC's Tom DiChristopher contributed to this report.