Iran is stockpiling crude on ageing tankers anchored in the Gulf after the US blockade curtailed exports. About 39 vessels now sit laden with Iranian oil and petrochemicals, up from 29 before April 13, with 13 more suspected near Chabahar port. US Central Command has redirected 72 ships and disabled four, effectively trapping Tehran's crude offshore.

Onshore storage has risen to roughly 64% capacity, about 10mn barrels, giving Iran a couple of weeks of additional production time. Kpler estimates the country has access to 24mn barrels of floating storage through idle tankers. A 30-year-old supertanker, unused for two years, began broadcasting its Gulf position at the end of April.

Before the conflict, Iran exported 40-60mn barrels monthly to Asian refineries. Now 20 vessels idle at Kharg Island versus 6 a month ago, and no cargoes loaded between May 6-14. Despite constraints, Tehran continues selling at premiums that fund the war effort.