Key Highlights

  • US commercial Crude Oil inventories, excluding the Strategic Petroleum Reserve, fell to 423.4 million barrels in the week ended September 11, 2026, down 0.6 million barrels, or 0.2%, from 424.1 million the prior week, according to data reported September 17, 2026.
  • US gasoline inventories rose 0.8 million barrels and distillate inventories rose 1.6 million barrels over the same week, while refinery utilization stood at 96.8% and crude processing ran at 17.3 million barrels a day.
  • The IEA's September 2026 Oil Market Report projected global oil Supply averaging 100.7 million barrels a day in 2026, down 5.7 million barrels a day year on year, while forecasting production rebounding by 8 million barrels a day in 2027 against Demand recovery of only 2.6 million barrels a day.
  • Global observed oil inventories plunged by a further 95 million barrels in August 2026 alone, according to the IEA, even as the agency's medium-term outlook points toward a large surplus forming once Gulf supply routes return to normal.

A Modest but Notable US Draw

US commercial crude oil inventories, excluding the Strategic Petroleum Reserve, fell to 423.4 million barrels in the week ended September 11, 2026, a decline of 0.6 million barrels, or about 0.2%, from 424.1 million barrels the prior week, according to data reported on September 17, 2026. Stocks remained about 1.9% above year-earlier levels, so the draw did not signal an acute domestic shortage, but it ran counter to the narrative of ample supply that has periodically weighed on prices. The Strategic Petroleum Reserve stood at 285.0 million barrels, down about 0.1% on the week and down 29.8% from a year earlier, reflecting the drawdown policy in place since the reserve was tapped heavily earlier in the conflict. Refined product inventories moved in the opposite direction: gasoline stocks rose 0.8 million barrels and distillate stocks rose 1.6 million barrels, while propane and propylene inventories fell 1.4 million barrels. Refiners ran hard to meet demand, processing 17.3 million barrels a day at 96.8% of capacity, with crude imports averaging 7.1 million barrels a day and four-week average product supplied at 20.5 million barrels a day, down 0.6% from a year earlier.

The IEA's Case for a Coming Surplus

Against that tightness in the weekly US data, the IEA's September 2026 Oil Market Report laid out a case for a global oil market moving toward surplus over the medium term. The report projected world oil supply averaging 100.7 million barrels a day in 2026, down 5.7 million barrels a day year on year, a decline driven primarily by more than 10 million barrels a day of Gulf output that remained shut in due to security risks tied to the conflict. Global oil demand was forecast to fall by 2.5 million barrels a day in 2026 as elevated prices curbed consumption, with the agency noting that global observed oil inventories plunged by a further 95 million barrels in August 2026 alone as the physical disruption to Gulf supply outpaced the demand slowdown. OPEC+ crude production fell to 33.11 million barrels a day in August, down from 34.57 million barrels a day in July, reflecting the same shut-in dynamics.

Reconciling Near-Term Tightness With a Medium-Term Glut

The apparent contradiction between a tightening US inventory picture and an IEA surplus warning resolves once the report's forward-looking projections are considered. The IEA forecast that global oil demand would recover by 2.6 million barrels a day in 2027, only narrowly offsetting 2026's losses, while global production was projected to rebound by a much larger 8 million barrels a day over the same period as disrupted Gulf supply, including flows through the Strait of Hormuz and Saudi Arabia's East-West Petroline pipeline, returns toward pre-war levels. That asymmetry, a large supply rebound against a comparatively modest demand recovery, is the basis for the agency's surplus warning: the current tightness reflected in weekly US data and the August global inventory plunge is a function of ongoing physical disruption, not of underlying market balance, and the IEA's own analysis implies that balance could flip sharply toward oversupply once Gulf routes normalize.

Where Things Stand

The September 2026 data present two views of the same market operating on different time horizons: a near-term US inventory draw and a sharp August global stock plunge point to genuine physical tightness tied to the ongoing conflict, while the IEA's medium-term projections warn that the eventual return of Gulf supply, including Hormuz shipping and Saudi pipeline flows, could outpace demand recovery and tip the market into surplus. How quickly that transition happens will depend heavily on the pace of any de-escalation between Iran and the United States, meaning both the weekly US inventory reports and the IEA's monthly balances are likely to remain closely watched, sometimes contradictory, indicators through the remainder of 2026.