Strategic Petroleum Reserve (SPR)

What the SPR is and where the oil is stored

Congress created the SPR in the Energy Policy and Conservation Act of 1975, after the 1973–1974 Arab oil embargo. Oil is stored in large caverns hollowed out of underground salt domes along the Gulf Coast. Salt caverns are cheap to build, the crude does not degrade, and the sites are close to refineries, pipelines and export terminals.

How the SPR releases oil

• Emergency sale. The president can order a drawdown during a severe supply interruption. Oil is sold to the highest bidders, as in 2022.
• Exchange (loan). The DOE lends crude to companies, which return it later with extra "premium" barrels. This was the main tool in 2026 and after hurricanes such as Katrina (2005) and Ida (2021).
• Congressionally mandated sales. Laws passed since 2015 required sales to raise revenue, regardless of market conditions. Some were cancelled after the 2022 release.
• International collective action. As a member of the International Energy Agency, the United States joins coordinated stock releases with other IEA countries.

The 2026 release: the largest collective action on record

After US and Israeli strikes on Iran on 28 February 2026 shut most traffic through the Strait of Hormuz, the IEA's 32 member countries agreed on 11 March 2026 to release 400 million barrels of emergency stocks. The U.S. share is 172 million barrels, which the DOE is supplying entirely as exchanges rather than sales. Companies borrow SPR crude now and must return it with a premium. The DOE says it expects about 200 million barrels back within a year, 20% more than it lent.

According to the DOE, four completed exchanges had awarded more than 133 million barrels by late September 2026, with a 25% premium in returned barrels. On 29 September it requested offers for a further exchange of up to 40 million barrels from Big Hill and Bryan Mound, for delivery in November and December 2026. On 2 October the G7 announced an additional coordinated release of 100 million barrels through the IEA over four months, with a front-loaded diesel component. In early October IEA Executive Director Fatih Birol said about 325 million barrels of the 400 million barrel action had been released.

The EIA's October 2026 Short-Term Energy Outlook expects the SPR to fall to about 242.5 million barrels by the end of 2026 and then to recover to about 345.7 million barrels by the end of 2027 as exchange barrels are returned.

The 2022 emergency release and the refill

After Russia invaded Ukraine, the U.S. government announced on 31 March 2022 that it would sell 180 million barrels from the SPR over six months, the largest release in its history at the time, alongside an IEA collective action. With congressionally mandated sales, stocks fell to 346.8 million barrels in July 2023, then a 40-year low. The DOE then bought crude back, mostly when WTI was below about $80, and lifted stocks to 415.4 million barrels by February 2026.

How SPR policy affects oil prices

SPR releases add supply in the short term. A release of 1 million b/d is significant against U.S. refinery runs of about 16.5 million b/d (EIA, week ending 2 October 2026), but small against the 10.9 million b/d of Middle East shut-ins at the peak of the 2026 disruption (EIA). That gap explains why Brent still reached $138.21 in spot trading on 7 April 2026 (EIA) despite the largest collective action on record.

Prices also react to the signal. Announcements tend to have an immediate effect on futures, but the market quickly looks at how much of the pledge is actually delivered and how it will be repaid. Exchanges add oil now and remove it later, so they tend to flatten the futures curve by lowering nearby prices relative to later months. Refill purchases do the opposite and can support prices. A depleted SPR also removes a buffer for future emergencies: in the Dallas Fed Energy Survey for the third quarter of 2026, the largest group of executives (31%) put the minimum safe SPR level at 100–150 million barrels, below the current level. For how stocks interact with the curve, see contango and backwardation.

Where to follow SPR levels

The EIA publishes SPR stocks every week in the Weekly Petroleum Status Report, on a separate line from commercial crude. The DOE announces sales, exchanges and purchases on its Office of Petroleum Reserves website.