- US Strategic Petroleum Reserve fell below 300 million barrels, lowest since 1983
- Reserve dropped 6.1 million barrels last week due to Iran war-related supply disruptions
- Trump authorised release of 172 million barrels after Iran disrupted Strait of Hormuz
The US Strategic Petroleum Reserve (SPR) has fallen below 300 million barrels, reaching its lowest level in more than four decades as the government draws heavily on its emergency oil stockpile amid disruptions in global crude supplies linked to the Iran war.
The reserve declined by 6.1 million barrels last week to 298.7 million barrels, according to US Department of Energy data. The latest figure puts the SPR at its lowest level since January 1983.
The sharp decline follows US President Donald Trump's decision in March to authorise the release of 172 million barrels after Iran disrupted oil shipments through the Strait of Hormuz. The move came as the conflict triggered an unprecedented disruption to global crude supplies and placed pressure on oil inventories.
SPR Could Fall Further
The current stockpile is already significantly below the level held before the conflict began.
The SPR contained roughly 415 million barrels before the US and Israel attacked Iran on Feb. 28. Once the full release ordered by Trump is completed, government stocks are expected to fall to around 243 million barrels.
The reserve has an authorised storage capacity of approximately 714 million barrels, meaning the current inventory represents less than half of its potential capacity.
Despite the steep decline, energy experts do not believe the SPR is immediately at risk of becoming unusable.
The minimum amount of crude required to safely operate the reserve is around 70 million barrels, according to an Energy Department spokesperson cited by CNBC.
David Goldwyn, a former State Department special envoy for international energy affairs, said the reserve still has sufficient oil for another emergency release if required.
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Ageing Infrastructure Adds To Pressure
The amount of oil stored in the SPR is not the only concern. Its ability to quickly release that crude has also come under scrutiny.
A May Government Accountability Office report found that more than a quarter of the reserve's oil was unavailable for drawdown as of December 2025 because of construction and underground cavern outages.
A July analysis by Rapidan Energy estimated that this could mean at least 103 million barrels of the current SPR inventory are not immediately deployable.
The findings highlight a growing challenge for Washington as the reserve is being used more frequently to respond to major energy disruptions.
US Has Used SPR Repeatedly
The latest drawdown follows several large-scale interventions by US presidents in recent years.
In early 2022, President Joe Biden ordered the release of 180 million barrels from the SPR after Russia's invasion of Ukraine created severe volatility across global energy markets. That release was the largest in the reserve's history.
Trump's current release comes as the global oil market faces another major supply shock tied to the Iran conflict.
With the SPR now below 300 million barrels, the latest data underscores how much America's emergency oil cushion has been reduced after years of large releases.
While the reserve still holds enough crude for another emergency response, its declining inventory and ageing infrastructure could make rebuilding America's strategic oil buffer an increasingly important policy challenge.
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