Iran’s 90 Million-Barrel Tanker Oil Reserve Is Exhausted, Kpler Says

Iran’s tanker-based oil reserve in Asian waters has fallen from nearly 90 million barrels to effectively zero, according to analysts at Kpler. The reported depletion removes the offshore buffer that allowed Iranian crude to keep reaching Chinese refineries when replacement cargoes could no longer move through the normal marine export chain.

Kpler said the inventory dropped below 1 million barrels by Oct. 5 and was fully exhausted by mid-October. Other tracking groups produced higher early-October estimates: Vortexa analyst Emma Li put the remaining volume off Singapore at about 6 million barrels on Oct. 9, while United Against Nuclear Iran estimated that Southeast Asian reserves had declined to 10 million barrels or less. The precise endpoint varies because tanker locations, cargo ownership and transfers can be difficult to determine, but all three estimates indicate a severe drawdown.

A large buffer built outside Iran

The reserve was part of a distributed storage and export system rather than a single terminal or tank farm. Iranian crude was moved to waters near Malaysia and Singapore, where loaded tankers could wait or transfer cargo to other vessels serving Chinese buyers. This gave the export chain inventory close to its principal market and separated the timing of production in Iran from the timing of final delivery.

Kpler estimated that Iran held about 135 million barrels overseas at the start of the war in February, much of it near Malaysia and Singapore. The first U.S. blockade on Iranian oil flows was imposed in April. After it was lifted during peace negotiations in mid-June, Iran rebuilt its overseas reserve to nearly 90 million barrels. The blockade was reimposed in mid-July, preventing replacement cargoes from replenishing the tanker network as stored oil continued to be discharged.

That sequence shows the practical value and the hard limit of floating storage. A reserve approaching 90 million barrels can sustain deliveries through a temporary interruption, but it remains a finite stock. Once outbound sales continue without inbound replacement cargoes, the network changes from a buffer into a countdown. In this case, almost the entire rebuilt reserve was drawn down between mid-July and early October.

Tankers provided more than storage

The vessels also functioned as transfer points. Ship-to-ship operations can move oil between tankers at sea or in sheltered waters, allowing cargoes to be consolidated, divided or redirected without using a conventional shore terminal. These operations require careful systems integration because two large vessels, their mooring arrangements and their cargo-handling equipment must work together under changing weather and loading conditions.

International requirements apply to oil tankers of at least 150 gross tonnage conducting such transfers. They must carry an approved operations plan, retain transfer records and use qualified overall supervision. Updated industry guidance submitted to the International Maritime Organization also emphasizes human performance, ship compatibility, fenders, hoses, mooring equipment and sequential safety checks.

Those controls illustrate why tanker storage is a specialized logistics capability, not merely empty volume. Floating inventory depends on suitable ships, cargo-transfer equipment, crews, coordination and a continuing stream of replacement oil. Removing the replenishment leg eventually disables the wider system even if some tankers and transfer capacity remain available.

Land routes cannot replace marine capacity

Iran has also stored oil in land-based tanks and moved supplies by truck to neighboring countries. Analysts said those routes cannot approach the volume carried by sea. Road transport divides a bulk marine cargo into far smaller loads and adds vehicles, drivers, border handling and repeated loading operations. It can preserve limited regional trade, but it does not reproduce the throughput of an oil-tanker network serving distant refineries.

The depletion is already changing procurement patterns. Li said Chinese refiners are increasingly seeking crude from Brazil and West Africa. That shift represents the downstream consequence of the storage loss: when Iranian cargoes held near Asia are no longer available, buyers must replace both the oil and the logistics that positioned it near their market.

U.S. Central Command estimated that the blockade had denied Iran at least $25 billion in oil revenue. Kpler analyst Homayoun Falakshahi said oil sales provide roughly 30% to 40% of Iranian government revenue and are its largest source of foreign exchange. Some payments from earlier Chinese purchases may continue arriving because settlement can take about two months, but that lag does not restore physical inventory.

The remaining constraint is capacity. Trucks and land tanks can move some oil, while delayed payments can temporarily soften the financial effect. Neither can substitute for nearly 90 million barrels of tanker-based inventory positioned along a marine route to Iran’s largest customer.

By Thomas Caldwell — AMI’s senior editor for mechanical and mobility engineering, covering vehicle electronics, systems integration, electrification, chassis systems, propulsion, and safety policy.