What happens to oil prices if the strait closes again

Brent settled at $88.40 a barrel on Jul 2, the ninth day of the 60-day fee-free passage window agreed in Muscat. That is roughly $22 above the 2025 average and roughly $60 below where the front month traded in the first week of March. Both numbers matter. The market has priced a working strait with an Iranian hand on the routing. It has not priced a closure.

This page sets out four scenarios for what crude does if that changes. Each carries a price range, a duration, and — more usefully — a short list of observations that would kill it. Scenario work that cannot be falsified is astrology with a spreadsheet, so the falsifiers are the part worth reading.

The arithmetic underneath all four is the same, and it is not complicated. About 20 million barrels a day of crude, condensate and refined product left the Gulf through the strait in 2024. Roughly 3.2 million barrels a day of that could be rerouted overland to loading points outside the strait, and only after a ramp measured in weeks. The remainder has nowhere else to go.

The four scenarios at a glance

The gaps between the rungs are wider than the ranges within them. That is deliberate. Between scenario 1 and scenario 2 sits a single question — whether buyers believe the interruption is a fortnight or a quarter — and the answer moves price more than any plausible change in the volume actually blocked.

Why OPEC spare capacity is trapped inside the Gulf

The standard reassurance after any Hormuz scare is that OPEC holds several million barrels a day of spare production capacity. It does. The problem is not whether the oil can be produced. It is where the oil has to be loaded.

• Saudi Arabia: about 2.6M b/d of spare capacity, concentrated at fields that export through Ras Tanura and Ju'aymah unless the East-West line takes them west.
• United Arab Emirates: about 1.0M b/d, of which at most 0.6M b/d can be moved to Fujairah on the Habshan line and loaded outside the strait.
• Iraq: about 0.3M b/d, all of it dependent on the Basrah terminals, which have no southern overland alternative.
• Kuwait: about 0.15M b/d, loadable only at Mina al-Ahmadi and Mina al-Bakr.
• Non-OPEC producers: no meaningful declared spare capacity. US, Brazilian and Guyanese supply responds in quarters, not weeks, and the first quarter of any response is inventory, not new barrels.

Add it up and roughly four million barrels a day of declared spare capacity exists, of which something under one million can reach a buyer if the strait shuts. Spare capacity that cannot be loaded is not spare capacity. It is stranded production, and in a closure it counts on the wrong side of the ledger — because the barrels the Gulf cannot ship are barrels the rest of the world has to find.

What the bypass pipelines can actually move

Two pipelines matter, and a third is frequently miscounted. Nameplate capacity is the number quoted in most coverage; unused capacity is the number that matters, because both working lines already run partly full in normal conditions.

Goreh–Jask is the line that gets miscounted. It exists, it has loaded cargoes, and its 300,000 b/d design capacity is real. But it is Iranian infrastructure, built precisely so that Iranian barrels can leave without passing a chokepoint Iran itself is closing. In any scenario on this ladder it serves Iranian exports and nobody else's, which is why the working total for the rest of the market is about 3.2 million barrels a day rather than 3.5.

The scenario ladder in detail

Scenario 1 — Brief disruption, 3 to 14 days

A mine strike, a grounding in a designated lane, or a seizure closes one lane while the interim understanding survives. This is the closest analogue to what the strait has actually delivered since Jun 24, including the container ship that went aground near Larak Island on Jul 1 with both lanes remaining usable. Price gaps higher on the headline, then bleeds as transit counts recover.

• Brent $105–125, with the curve staying in backwardation and the spike concentrated in the first two contracts.
• War-risk premium on hull value rises from roughly 0.85% to 1.5–2.0%, adding perhaps $0.40 a barrel to a laden VLCC transit.
• No coordinated reserve release; individual governments issue statements rather than barrels.
• Front-month implied volatility above 60%, but December contracts move less than $8.

Scenario 2 — Partial closure, 4 to 8 weeks

The 60-day fee-free window expires without renewal and routing designation is used to throttle rather than to stop traffic. Transit falls to roughly half of the pre-crisis baseline. This is the scenario the current agreement is designed to prevent, and it is the one where the bypass pipelines earn their keep — they cover about a third of the shortfall, provided the ramp goes well.

• Brent $130–160, with the whole curve lifting rather than just the prompt.
• Petroline and ADCOP pushed toward maximum throughput; Red Sea and Gulf of Oman freight rates decouple from Gulf rates.
• IEA members consult on a collective action; a release of 1.0–1.5M b/d for 60 days is the historical template.
• Qatari LNG cargoes begin to be declared force majeure — the piece of this scenario with no crude analogue and no bypass at all.

Scenario 3 — Sustained closure, 60 to 120 days

Transit is denied outright and contested in the approaches. Roughly 17 million barrels a day of the pre-crisis flow has no route. Commercial and strategic inventories become the marginal barrel, and the price stops being about supply and starts being about how fast stocks draw. Expect intraday prints well above the settlement range as thin screens absorb forced hedging.

At this rung the market is no longer pricing oil. It is pricing the number of weeks until inventories run out, and every headline is a revision to that number.

straitofhormuzs.com desk

Scenario 4 — Closure plus strikes on export infrastructure

The tail. A closure accompanied by damage to loading terminals, stabilisation plants or the bypass lines themselves converts a routing problem into a capacity problem, and capacity takes months to rebuild rather than days to reopen. Nothing on the historical record prices this cleanly, which is the honest reason the range is 100 dollars wide.

• Brent $250–350, with settlement ranges unreliable and exchange circuit breakers in play.
• Physical allocation replaces price as the rationing mechanism in importing countries; retail controls follow within weeks.
• Reserve releases become continuous rather than episodic and are exhausted as a policy tool inside a quarter.
• Demand destruction, not supply response, closes the balance — the mechanism described two sections below.

How strategic reserves would be used

Emergency stocks are the only supply that can arrive in days rather than quarters, and they are the most misunderstood instrument on the board. Three constraints govern them: inventory level, maximum drawdown rate, and the political willingness to spend a buffer that takes years to refill.

1. A member government notifies the IEA secretariat and a collective action is proposed; in practice this has taken between four and eleven days from the triggering event.
2. Each participating country commits a volume, drawn from public stocks, from obligations placed on industry, or from demand-restraint measures counted toward the same total.
3. US volumes are offered through a competitive sale from the Gulf Coast caverns; bids are accepted and delivery scheduled, which adds roughly 13 to 15 days before the first barrel moves.
4. Barrels reach refiners as crude, not product, so the pump effect lags the announcement by a further two to four weeks.
5. Refill begins only once prices fall back, which historically has meant years — the reason governments treat the second release far more cautiously than the first.

Against scenario 2, a coordinated release of 1.0–1.5M b/d is meaningful but partial — roughly a fifth of the shortfall the pipelines cannot cover. Against scenario 3 it buys perhaps six to eight weeks. Against scenario 4 it is a rounding error that is spent early and is not available later.

Where demand destruction sets the ceiling

Every scenario has a ceiling, and it is not set by supply. Short-run price elasticity of demand for crude runs somewhere between -0.02 and -0.04 over a single quarter — consumers cannot change their vehicles, heating systems or supply chains quickly, so the response is small at first and then compounds. At $200 Brent, roughly 130% above the current base, that implies 2.5 to 4 million barrels a day of demand removed within two quarters.

Most of that reduction lands in non-OECD Asian road fuel and in industrial switching, not in OECD driving. It arrives too slowly to cap a three-week spike and fast enough to cap a six-month one, which is the mathematical reason scenario 3 has a range at all rather than an open upper bound. The pass-through arithmetic from Brent to the forecourt — roughly 24 cents a gallon per $10 a barrel, with a two-to-six-week lag — is set out separately on /guides/pump-price.

What would falsify each scenario

Each row below is a specific, checkable observation that should make you discard the scenario rather than adjust it. If a scenario survives every falsifier for a fortnight, its weight goes up. If one trips, the weight moves to the rung above or below the same day.

How we update this page

The status banner and transit figures on this site are refreshed daily at about 06:00 UTC. This page is reviewed against that refresh and rewritten whenever a falsifier trips, a scenario weight moves by more than five points, or the interim understanding changes state. The date at the top is the last substantive revision, not the last time a number was checked.

Two things would prompt a full rebuild of the ladder rather than an edit: renewal of the passage window on materially different terms, or any confirmed change to bypass pipeline capacity in either direction. Until then the base case remains a restricted strait that stays open — which is what the market is currently paying for.