The US Strategic Petroleum Reserve (SPR) is the world’s largest government-held emergency oil stockpile. It exists to cushion the country — and, indirectly, world markets — against a serious supply disruption.
What it is and where it’s held
The SPR is crude oil stored in deep underground salt caverns along the US Gulf Coast in Texas and Louisiana, with an authorised capacity of around 714 million barrels. Salt caverns are used because they are cheap, secure and can be drawn down relatively quickly in an emergency.
How releases work
The government can release oil in a few ways: an emergency sale during a serious supply interruption, a smaller “test” or exchange release, and exchanges where companies borrow crude and return it later plus a premium — which is different from an outright sale. Large drawdowns lower the reserve’s level and are watched as a sign of how much cushion remains.
Why the level matters
A well-stocked SPR gives policymakers a tool to calm prices during a shock; a depleted one removes that option and can itself become a market signal. Because it is reported weekly by the EIA, the SPR level is one of the clearest gauges of US energy resilience.