Crude oil inventories in the U.S. Strategic Petroleum Reserve (SPR) have fallen below 300 million barrels for the first time in more than four decades as global energy supplies remain under pressure from the Iran conflict.
Strategic Petroleum Reserve Hits Lowest Level Since 1983
The SPR declined by 6.1 million barrels last week to 298.7 million barrels, according to data released by the U.S. Department of Energy. The reserve, established in 1975, is now at its lowest level since January 1983.
The drop follows President Donald Trump’s decision to authorize the release of 172 million barrels in March after Iran restricted oil exports through the Strait of Hormuz, creating the largest disruption to crude oil supplies in history.
Concerns Grow Over Future Emergency Supply Capacity
The SPR has an authorized storage capacity of approximately 714 million barrels, but the recent drawdown has raised questions about how much emergency supply remains available for future disruptions.
The U.S. Energy Department said in July that the minimum amount of oil needed to safely operate the reserve is approximately 70 million barrels.
Despite the decline, former State Department special envoy for international energy affairs David Goldwyn said the reserve still has enough oil available for another emergency release if required.
“I’m not worried about the stability of the reserve or our ability to do another drawdown, if we needed to,” Goldwyn said.
Infrastructure Issues Limit SPR Availability
The SPR held around 415 million barrels before the United States and Israel launched attacks on Iran on February 28. Once the full release ordered by Trump is completed, government-held oil stocks are expected to fall to approximately 243 million barrels.
However, the reserve’s ability to respond quickly to future crises has been affected by aging infrastructure. A May report from the Government Accountability Office (GAO) found that more than a quarter of SPR inventory was unavailable for drawdown as of December 2025 due to construction and storage cavern issues.
A July analysis by Rapidan Energy estimated that at least 103 million barrels of SPR inventory may currently be unavailable for use.
The GAO warned that the reserve’s drawdown, distribution, and refilling capabilities remain limited due to long-term infrastructure problems combined with ongoing maintenance projects.
Recent Presidents Have Used the Reserve More Frequently
Large-scale releases from the SPR have become more common in recent years. In 2022, President Joe Biden authorized the release of 180 million barrels following Russia’s invasion of Ukraine and rising global energy market volatility.
The GAO described that release as an “unplanned stress test” for the reserve, highlighting the challenges of maintaining operational readiness after major drawdowns.
Goldwyn said frequent use of the reserve can accelerate wear on its infrastructure and equipment, making maintenance increasingly important.
