The International Energy Agency said on September 11, 2026, that the global oil market faces a deeper 2026 supply contraction than it had forecast a month earlier, with the return of normal Gulf flows pushed into 2027. The agency projects world oil supply will average 100.7 million barrels per day this year, a 5.7 million-bpd decline from 2025, as security risks and an unresolved United States-Iran standoff keep more than 10 million bpd of Gulf output shut in. [1] [2]
The same report lowers its demand outlook: global consumption is expected to fall by 2.5 million bpd in 2026, 940,000 bpd more severe than the previous monthly estimate. August inventories fell by 95 million barrels, while refinery and tanker disruptions have left refined products, particularly diesel, tighter than crude. The current status is therefore a market being balanced by stock withdrawals and reduced consumption, not a return to normal supply conditions. [1] [2]
Key points
- The IEA expects 2026 world oil supply to average 100.7 million bpd, down 5.7 million bpd year on year. [2]
- Global oil demand is forecast to decline by 2.5 million bpd in 2026 before recovering by 2.6 million bpd in 2027. [2]
- August production fell 1.6 million bpd from July to 100.1 million bpd, with more than 10 million bpd of Gulf output shut in. [2]
- Observed inventories dropped 95 million barrels in August; cumulative draws since February reached 507 million barrels. [2]
- OPEC’s separate forecast still calls for 2026 demand growth of 380,000 bpd, illustrating a major difference in institutional assumptions. [1]
What happened in September
The IEA’s September Oil Market Report, published September 11, incorporated continued disruption in Middle Eastern energy flows and a lack of progress in negotiations between the United States and Iran. It cut both supply and demand estimates and said a full recovery in Middle East production would be deferred until 2027. The forecast is a conditional assessment of conditions known at publication, not a statement that a permanent production loss has occurred. [2]
The immediate supply data were already weak. Global production in August was estimated at 100.1 million bpd, down 1.6 million bpd month on month. The IEA attributed the fall largely to security risks that kept more than 10 million bpd of Gulf production offline. Reuters reported that Saudi Arabian crude supply fell 2.3 million bpd in August to about 6 million bpd, described by the IEA as the country’s lowest level in more than three decades. [1] [2]
Verified background and market context
The IEA’s supply estimate combines an August production shock with a delayed recovery assumption. Non-OPEC+ producers in the Americas are expected to provide some offset, adding 1.4 million bpd in 2026 and 1 million bpd in 2027. Even with that growth, total supply is forecast to rebound by 8 million bpd in 2027 if disrupted flows return. These are forecasts, not guaranteed outcomes. [2]
Demand is moving in the opposite direction because higher fuel prices and lost feedstocks are weighing on consumption. The IEA says the projected 2.5 million-bpd decline in 2026 should ease from a 5.3 million-bpd contraction in the second quarter to 3.4 million bpd in the third quarter and 2 million bpd in the fourth. The agency expects demand to rise 2.6 million bpd in 2027, narrowly offsetting this year’s projected loss. [2]
The demand disagreement with OPEC is material. Reuters reported that OPEC, despite reducing its estimate for a fifth consecutive month, still sees world oil demand increasing by 380,000 bpd in 2026 and by 2.36 million bpd in 2027. The two institutions use different assumptions and methodologies, so their numbers should be read as separate scenarios rather than combined into a single consensus. [1]
Refining and inventories
The most acute pressure is in refined products. Global refinery throughput reached 81.4 million bpd in August, 4.2 million bpd below a year earlier even after a monthly increase of 960,000 bpd. The IEA says margins reached record levels in the Atlantic Basin, led by diesel, while freight costs hurt profitability in Singapore. [2]
Gulf refined-product and liquefied-petroleum-gas exports were estimated at nearly 60%, or 3.7 million bpd, below February levels. Gulf diesel and gasoil net exports averaged 390,000 bpd in August, just over a quarter of their pre-war level. Disruptions to Russia’s refining system compounded the loss: combined Gulf and Russian diesel/gasoil exports were 1.6 million bpd below February. [2]
Inventories have absorbed part of the shock. The IEA estimates that observed global oil stocks fell 95 million barrels in August, or 3.1 million bpd, taking cumulative draws since February to 507 million barrels, equivalent to an average 2.8 million bpd. Non-OECD inventories fell 52 million barrels, led by China, while OECD stocks rose 23 million barrels as commercial builds exceeded a 19 million-barrel draw in government stocks. [2]
Why it matters for readers
For households and businesses, the immediate exposure is through transport fuels rather than a single crude benchmark. The IEA says losses will be concentrated in middle distillates and petrochemical feedstocks, especially in Asia. [2]
For oil-consuming economies, shrinking inventories reduce the cushion available when a shipment is delayed or a refinery stops. The IEA says the refining system is stretched and that further tightening could produce demand destruction, although the outcome depends on security, alternative supply and refinery availability. [2]
What remains uncertain
The largest uncertainty is the timing and scale of restored Gulf production. The IEA’s 2027 recovery assumption depends on improved security and the resolution of the United States-Iran conflict, while Reuters described attacks on shipping and energy infrastructure as active factors in the September assessment. A ceasefire, protected shipping lanes or a faster restart could improve supply sooner; renewed attacks or prolonged closures could delay it. These are scenarios, not verified developments. [1] [2]
The demand path is also unsettled. High prices can reduce fuel use, but economic activity, substitution, weather and government policy can change the response. The divergence between the IEA’s projected 2.5 million-bpd decline and OPEC’s 380,000-bpd increase shows how sensitive the result is to underlying assumptions. Neither forecast should be presented as a guaranteed market outcome. [1] [2]
Inventory totals are estimates that describe the buffer in the IEA’s assessment; they do not identify exactly when individual countries or companies would face shortages. [2]
What happens next
The next developments to watch are concrete rather than speculative: whether Gulf production restarts, whether tanker traffic through affected routes normalises, whether refineries restore lost runs and whether inventory draws slow. The IEA will update its supply, demand, stock and refining estimates as new data arrive. [2]
Until then, the September report presents a two-sided market. Supply is falling faster than expected, but demand is also weakening under higher fuel costs. Inventories are bridging the gap for now, while the agency’s deferred 2027 recovery assumption leaves the outlook dependent on security and diplomacy. OPEC’s more positive demand view reinforces that the central forecast remains contested, not settled. [1] [2]
