How Low Can the Strategic Petroleum Reserve Actually Go?

The U.S. Strategic Petroleum Reserve (SPR) reached its lowest level on record at the end of September 2025, with only 283 million barrels of oil stored, according to Reuters. This is the lowest level since October 1982, a time when the reserve was being filled for the first time. While the current barrel count is alarming, the main challenge lies in replenishing the reserve, which is slower, more expensive, and dependent on factors beyond control.

The SPR was established in 1975 following the Arab oil embargo, aiming to protect the U.S. from dependence on foreign oil. It peaked at 726.6 million barrels in 2009 before declining steadily through the 2010s due to various factors. In 2022, the Biden administration drew down the reserve by 180 million barrels in response to Russia's invasion of Ukraine, the largest sustained drawdown in the reserve's history.

By the end of 2023, the SPR had dropped to 354.7 million barrels. Recently, the SPR came to the aid during the February 2026 attacks on Iran, entering the situation with approximately 415 million barrels, or 58% of its authorized capacity. In March, the U.S. committed 172 million barrels to a 400-million-barrel release coordinated by the International Energy Agency, with a 172% premium for early repayment.

While the Department of Energy claims there is ample room for the reserve, experts warn that a drop below 300 million barrels could jeopardize the system's integrity.