Oil futures gave up early gains and settled lower Wednesday as traders looked past fresh Houthi attacks in Saudi Arabia and production shut-ins off the U.S. Gulf coast and focused on continuing oil flows out of the Middle East.

Brent crude for December delivery settled down 0.4% at $100.20 a barrel after rising to as high as $102.59. West Texas Intermediate crude for November delivery fell 1.3% to $88.28 a barrel.

Futures have declined in three of the past four sessions on optimism about the amount of oil that is making it out of the Persian Gulf despite the conflict remaining unresolved.

"I think people are looking at the markets with a positive lens and the expectation is that we're getting close to 90% of flows through the Strait of Hormuz," said Chris Cook, a research analyst at Frost Investment Advisors. "If it wasn't for the fuel costs for the transportation and the insurance that's getting tacked on, we'd probably be in a much lower price environment right now."

Saudi Arabia's General Authority of Civil Aviation said Tuesday that King Abdullah bin Abdulaziz International Airport in Jazan and Najran International Airport were damaged in attacks.

Early Wednesday, a Houthi missile targeting an area north of Riyadh was intercepted and destroyed, according to a spokesperson for the Saudi-led coalition. An attack also targeted Aden International Airport in Yemen, where authorities said two Houthi missiles struck the civilian facility without causing injuries, The Wall Street Journal reported.

The Saudi-led coalition separately said Tuesday that it destroyed a ballistic-missile launch platform in Sana'a and a storage facility at a mountainous site in Saada containing 20 ballistic missiles, according to the Saudi Press Agency.

Shipping risks around the Strait of Hormuz also remain elevated. An attack Tuesday wounded 12 mariners aboard the Panama-flagged commercial vessel MT On Peace, including 11 Indian nationals, India's foreign ministry said.

Tropical Storm Isaias formed in the Gulf of Mexico and is expected to reach the U.S. Gulf coast between Mississippi and Alabama late Friday as a hurricane, according to the National Hurricane Center. The U.S. Marine Minerals Administration said Wednesday that eight platforms and two rigs had been evacuated, with 511,619 barrels a day of oil and 350 million cubic feet a day of natural gas production shut in.

The U.S. Energy Information Administration said Wednesday that U.S. commercial crude oil inventories fell by 3.2 million barrels last week to 424.1 million barrels, and were about 1% above the five-year average for the time of year. The market had expected a third consecutive weekly inventory build.

On Tuesday, the EIA estimated that Middle East oil exports

increased in September from August despite continued attacks, while crude-production shut-ins fell to an average 4.8 million barrels a day from 5.8 million barrels a day in August and 10.9 million barrels a day at their May peak.

The improvement in regional flows has eased some supply concerns, but the market remains exposed to renewed disruptions. "There is a clear tug-of-war at the moment between improving supply from the region and lingering threats to supply," analysts at ING said. Brent's front-month spread was around $3 a barrel Wednesday, up from a one-week low of $2.38 overnight, suggesting nearby supply remains relatively tight, analysts at MUFG said.

The EIA raised its fourth-quarter Brent forecast to an average $105 a barrel, $14 above its previous forecast, saying Middle East export constraints, high transportation costs and declining inventories should keep prices elevated. It estimates global oil inventories fell by 1.9 million barrels a day in the third quarter and expects a further 700,000-barrel-a-day decline this quarter.

Tightness is particularly visible in refined fuels. Shell said Wednesday that its refining-margin marker is expected to reach a record $42 a barrel in the third quarter, up from $24 in the second quarter. The previous record was $28.04 a barrel after Russia's 2022 invasion of Ukraine.

Middle-distillate markets have eased from September highs, with the ICE gasoil crack falling to around $73 a barrel from just above $90 last month, analysts at ING said. European strategic diesel releases and a lower risk of a U.S. diesel-export ban have eased pressure at the front of the market, but longer-dated cracks remain better supported because Persian Gulf and Russian diesel flows remain constrained, they said.