Iran's oil exports fell to their lowest level in at least six years in May as the U.S. naval blockade continued to choke off crude shipments and leave tens of millions of barrels stranded at sea.
According to shipping data from Vortexa, Iran exported just 209,000 barrels per day (bpd) of crude oil and condensate in May, down from 1.34 million bpd in April and nearly 1.9 million bpd in March. Kpler had estimated May exports slightly higher at 260,000 bpd, but still the lowest level since the height of the Trump administration's "maximum pressure" campaign in 2019-2020.
When the blockade first took effect in April, analysts expected Tehran to lean on floating storage while waiting for an opportunity to move barrels. But storage is no longer growing. According to Kpler, floating inventories have fallen from roughly 190 million barrels in late April to about 147 million barrels today as cargoes continue trickling into China and production slows.
The problem for Tehran is that China's appetite is cooling just as Iran needs buyers most.
Chinese imports of Iranian crude fell to 1.1 million bpd in May, the lowest level since January 2025. Independent Chinese refiners have begun cutting processing rates amid weak margins and comfortable fuel inventories, reducing demand for sanctioned barrels. That shift has already pushed Iranian Light crude from premiums to discounts against Brent for the first time in two months.
Meanwhile, roughly 67 million barrels of Iranian crude and condensate remain stranded inside the Gulf and Gulf of Oman, according to Kpler estimates.
Analysts say time may be running short. Kpler's Homayoun Falakshahi warned that if the blockade remains in place for another two months, Iran could effectively run out of available oil to ship to China.
The market implications extend beyond Iran. Every barrel removed from export markets tightens an already strained global supply picture at a time when Middle East disruptions have already slashed regional exports.
For now, fewer tankers leaving Iran means fewer barrels reaching buyers. Eventually, it will mean fewer barrels being produced.
By Julianne Geiger for Oilprice.com
