Iran could fill its crude storage within 12-22 days if a US naval blockade of the Strait of Hormuz continues, analysts say. The blockade, in place since April 13, has forced Tehran to hold oil at home rather than ship it from Kharg Island, the country's main export terminal. Bloomberg cited Kpler data that set the tight timeframe, and United States Treasury Secretary Scott Bessent warned Kharg's tanks could be full "in a matter of days." A sustained squeeze on exports would cut physical supply from Iran and could tighten global flows that pass through the strait.

Blockade and the chokepoint

The Strait of Hormuz links the Gulf to the open ocean. It runs along Iran's northern coast and Oman's southern coast. About 20 percent of the world's oil and liquefied natural gas moves through that narrow corridor during normal times. That's why activity in the strait matters far beyond the region.

The United States imposed a naval blockade on Iranian ports and the strait on April 13. The move followed military strikes earlier in the year. Two days after those strikes, Ebrahim Jabari, a senior adviser to the commander in chief of Iran's Islamic Revolutionary Guard Corps, said the strait was "closed" and that Iranian forces would attack ships that tried to pass. Iran later allowed some friendly vessels and those that paid tolls to transit. But since the blockade began, Tehran has stopped allowing foreign-flagged ships to pass until the United States lifts its measures.

The blockade has produced direct confrontations at sea. The United States opened fire on and then seized control of an Iranian-flagged tanker near the strait. Iranian authorities called that action illegal and labelled it "piracy." Those seizures and interdictions have cut the flow of tankers carrying Iranian crude to markets and pushed the Islamic Republic to keep more oil inside its ports and storage tanks.

How close is storage to capacity?

Shipping and storage analytics firm Kpler analysed satellite and tanker-track data to estimate remaining storage in Iran. Bloomberg reported Kpler's work on Tuesday. Kpler's estimate put the window for running out of storage at roughly 12 to 22 days if exports stay blocked.

That range depends on how much oil Iran keeps pumping and how much it can quickly load onto tankers that are still able to sail.

Mastheads

United States Treasury Secretary Scott Bessent said last week that Kharg Island, Iran's main export terminal, would be full "in a matter of days." Kharg Island handles most of Iran's overseas crude, and roughly 90 percent of the country's exports move through that port for shipment through the Strait of Hormuz. Iran is OPEC's third-largest producer after Saudi Arabia and Iraq, so any severe restriction on its exports reverberates in the broader oil market.

Analysts have warned that if storage fills, Iran would face two basic choices. One is to halt or scale back production so oil doesn't keep building up onshore. The other is to keep producing and find ways to store crude afloat, which requires tankers and insurance arrangements. Some analysts mentioned gradual production cuts if the blockade persists; others highlighted logistical limits that make an immediate, large-scale pivot difficult.

Why filled tanks matter for markets

Tanks reaching capacity in Iran would change the physical balance of supply. Oil that can't be exported is oil that doesn't reach refineries and traders abroad. That removes a portion of global supply that normally competes in world markets. The Strait of Hormuz already channels one-fifth of global oil and LNG, so disruptions there have oversized effects on trading flows.

Fewer Iranian barrels on world markets would reduce the volume available for buyers outside Iran. That could mean tighter supply for refiners that source crude through the Gulf. Traders and refiners typically adjust by drawing on inventories, shifting cargoes from other suppliers, or buying cargoes at higher prices. The article's sources didn't give a specific price effect. But the mechanics are clear: blocked exports reduce actual barrels moving through a crucial chokepoint.

Storage constraints also create practical headaches for Iran. Kharg Island's facilities are built for loading and dispatch, not indefinite storage. Ports that hold crude need regular ship arrivals and departures. If tanks stop turning, costs rise. Ships that could pick up cargoes may be diverted or delayed. Those delays raise insurance and operational costs. Some operators will avoid the area, shrinking the pool of available tankers and complicating any plan to keep crude at sea.

Political fallout and regional risk

The maritime standoff has a political dimension. Iranian officials framed the restrictions as a response to foreign military pressure. Mohammad Reza Aref, Iran's First Vice President, said on April 19 that "the security of the Strait of Hormuz isn't free." He added that restricting Iran's oil exports while expecting free movement for others was untenable and warned that costs would follow.

On the other side, Washington has enforced its blockade through naval action and interdictions. The United States views the measures as a way to limit Iran's ability to fund or support military operations. Tehran describes the same moves as illegal and provocative. The seizure of a tanker and the exchanges at sea increase the risk of further incidents that could interrupt shipping beyond Iranian exports.

Those risks matter because any escalation that affects shipping safety can widen the disruption. If insurers raise premiums for tankers in the Gulf, or if major shipping lines reroute around longer paths, the result will be higher transport costs and slower cargo rotations. That combination would further squeeze flows from the Gulf. The immediate effect is operational. The broader effect is that buyers reassess where they source barrels.

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US officials warn Kharg Island's tanks could be full "in a matter of days." If storage fills, Tehran would likely curb production or keep oil afloat, tightening flows through the Strait of Hormuz.

This article was created with AI assistance.