Crude benchmarks logged a second consecutive weekly gain, driven by the collapse of US-Iran diplomatic talks, severe disruptions in the Strait of Hormuz, and potential new US economic sanctions on Iran.
West Texas Intermediate settled at $86.64 per barrel, up from $82.40/bbl the previous week, while Brent closed at $93.70/bbl, up from $88.73/bbl a week earlier.
Both benchmarks gained almost 6% over the week.
The rally was primarily fueled by geopolitical tensions, stalled diplomatic efforts between Washington and Tehran, and persistent disruptions to regional energy flows, market analysts said.
"The lack of a solution in the Middle East continues to raise oil prices, which have now risen for several days in a row," Pia Fromlet, an economist at SEB Research, said in a Friday note.
The week began under heavy pressure as the interim 60-day peace framework set out under the Islamabad Memorandum of Understanding expired without a permanent peace agreement or an extension.
Following this, tensions escalated sharply when the UAE halted all trade and financial transactions with Iran, accusing Tehran of launching ballistic missiles at its territory, an allegation denied by Iranian officials.
Ship-tracking data show that commercial vessel traffic through the critical Strait of Hormuz remained heavily constrained due to ongoing security risks and attacks, with confirmed daily crossings plunging to multi-month lows and Middle East refinery runs remaining severely depressed.
Throughout the week, market sentiment was heavily driven by escalating political rhetoric and policy moves.
President Trump threatened sweeping "economic warfare" against Iran, vowing severe secondary consequences for any nation or entity offering Tehran an economic lifeline.
Echoing this stance, US Treasury Secretary Scott Bessent announced plans for a tough new sanctions package, further intensifying pressure on Iran's economy.
Bessent said he would disclose details on the new measures on Monday.
"The US administration is expected to provide details on Monday about how it intends to further isolate Iran's economy, with traders concerned that tougher measures could trigger significant blowback from China, a key trading partner and buyer of Iranian oil," Saxo Bank analysts said.
The potential for a Chinese response adds another layer of uncertainty to an already tight market, keeping attention focused on the broader risks to regional energy supplies.
"The measures are expected to target Tehran directly, while potentially extending to countries that continue doing business with Iran, including China," analysts at Aegis Hedging said in a Friday note.
Aegis cited Rystad Energy's forecasts that Chinese crude purchases could increase by up to 1.2 million barrels per day from Q3 through year-end 2026 after the world's largest crude importer reduced purchases and refinery runs in response to the Middle East-driven price spike.
"With the Middle East crisis showing few signs of easing, the risk of further disruption to regional energy flows continues to support crude and refined product prices," Saxo Bank analysts noted.
Despite Washington's claims that the Strait of Hormuz is open, vessel transit volumes remain severely limited, and recent attacks on infrastructure in Saudi Arabia and commercial vessels have kept a hefty geopolitical risk premium priced into the market.
"Washington's harder economic stance toward Iran and the lack of progress toward reopening the Strait of Hormuz continue to keep a substantial supply premium in the market," Gelber & Associates said.
On the supply side, the Energy Information Administration reported a 4.4-million-barrel build in US commercial crude inventories for the week ended Aug. 14, bringing stocks in line with the five-year average.
The build is above Macquarie's estimate of a 3.9-mmbbl inventory rise for the week ended Aug. 14.
"The commercial stock build was driven by higher domestic supply despite strong export demand and lower imports," ING analysts noted.
The US oil rig count decreased by three, from 455 the previous week to 452, in the week ending Aug. 21, according to data from Baker Hughes (BKR) released Friday. That compares with 411 oil rigs in operation a year earlier.
The consolidated North American rig count, a key early indicator of future production levels, dropped by eight to 804 from 812 the previous week.
Money managers in the WTI crude futures and options markets maintained their net long positions in the week ended Aug. 18, according to the Commodity Futures Trading Commission's latest Commitments of Traders report released Friday.
The data showed that money managers reported 195,631 long positions, up 3,126 from Aug. 11, while short positions were up 2,805 to 91,596.
Money managers' net long position increased marginally by 321 contracts to 104,035 contracts from 103,714 the previous week. This indicates little change in bullish positioning despite the rise in crude prices.
Meanwhile, security risks also remain elevated beyond the Strait of Hormuz. A US-sanctioned tanker reportedly sailing under a false flag was hijacked in the Gulf of Aden and redirected toward Somalia, according to MarineTraffic on Thursday.
Six armed individuals reportedly boarded the tanker and took control of the vessel.
MarineTraffic data showed that the 32,200-deadweight-ton oil products tanker updated its AIS destination to Port Sudan on Aug. 14 and entered the Somalia "high-risk" area on Aug. 19.