Inside Iran’s 6-Week Countdown to Oil Tank Tops

Energy Aspects completes acquisition of Kayrros.

Iranian crude inventory levels have increased by roughly 13 MMb since the blockade was implemented. Iran has 22 MMb of spare storage capacity remaining, based on an 80% maximum utilization of design capacity.
At current build rates, Iran currently has an estimated six weeks before reaching tank tops, or about two weeks based on pre-war export rates. A near-total blockade of its oil exports threatens to shut in production.
Floating storage is slowing down the onshore build. Tanker loadings have allowed Iran’s onshore crude storage network to build by just 500 kb/d since the blockade began, despite normally exporting 1.7 million barrels per day.
The United States is targeting Iran’s spare floating storage, which could shorten the timeline to tank tops.

Onshore crude inventories have built at a fraction of blockaded export levels, averaging just 500 kb/d since the near-total blockade of the country began.
Iran currently has about 22 million barrels of effective spare storage capacity (assuming a maximum fill rate of 80%), about six weeks to tank tops at the current build rate and equivalent to 13 days of normal crude and condensate exports, which averaged 1.7 million barrels per day in 2025.
Iran’s capacity to keep producing at normal levels without exporting is greater than that of Arab Gulf producers at the onset of the war.
Iranian inventories have built by 13 million barrels since the start of the US blockade on April 13.
Iranian crude stocks reached a record high of more than 92 MMb in May 2020, at the peak of the Covid pandemic, filling 85% of nameplate storage capacity. At that time, this appeared to signal “tank-tops.” Iran has since expanded its tankage by 16 mb, so that Covid-level stocks would only fill 75% of today’s capacity. Had capacity remained at COVID levels, Iran would only have two weeks of runway left.

Tanker loadings at Kharg Island have slowed the fill rate of Iran’s crude oil storage tanks.
The count of idle vessels near Kharg Island has climbed to 19, but no new loadings have been detected since May 6, according to Energy Aspects.
The US Navy recently targeted two empty Iranian tankers near Hormuz, in an effort to expedite the blockade’s impact on Iran’s oil sector. This loss of tonnage constrains Iran’s ability to mitigate onshore builds.
With a 77% fill rate, Kharg Island’s storage levels remain below peak levels seen in 2020 (89%), though not by much. Iran will need to tap other facilities to store excess crude oil.
Despite loading 90% of Iranian exports before the war, Kharg Island comprises only 25% of Iran’s onshore crude storage capacity. Kharg has built by nearly 5 million barrels since the blockade began, more than any other facility in Iran during the same time period.

The blockade extends to all of Iran’s coastline, not just ports behind the Strait. This means its crude exports are near zero.
Goreh reaches tank top levels at over 90% fill capacity. The facility, which was recently completed last year, feeds the pipeline to Jask, which bypasses the Strait of Hormuz.
Jask is just under 50% fill level but filling up quickly as tanker loadings slow down and Kharg Island fills up.
Jask built by more than 1.6 MMb in the past week, the most of any facility in Iran.

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The US blockade is putting pressure on Iran, but its oil industry can still hold out