Iran's Oil Reserves Plummet Under US Blockade

Iran's floating oil reserves have dropped dramatically in recent weeks, falling from approximately 90 million barrels in late July to just 29 million barrels. This drastic decline is largely due to the naval blockade imposed by the US, which has severely restricted Iran's ability to export oil.

According to data from commodity intelligence firm Kpler, no Iranian crude oil cargo has crossed the blockade line since the naval blockade was resumed on July 14. Despite this, Iran continues to load limited quantities of oil onto tankers within the Persian Gulf, but these shipments are unable to reach foreign markets.

In the one-month period leading up to early September, Iran loaded approximately 255,000 barrels of oil per day within the Persian Gulf, an 85% drop compared with average daily loadings in the months preceding the war. This reduction in exports has forced Tehran to curtail domestic production, with Homayoun Falakshahi, lead crude analyst at Kpler, noting that relatively stable domestic inventory levels despite a sharp collapse in exports indicate that Iran's oil production has dropped to levels near domestic demand.

The blockade pressures have also reached the petrochemical sector, which relies heavily on maritime transport. Kpler estimates that petrochemical product loadings through early September fell by approximately two-thirds compared with the winter of 2025-2026. In response to these restrictions, Iran has shifted some commercial transactions toward routes involving Turkey, Iraq, Oman, Pakistan, Russia, and the Caspian Sea; however, these channels offer limited capacity and impose higher costs and delays on trade.