The engineering behind the US Strategic Petroleum Reserve
a day ago
- The US Strategic Petroleum Reserve must store hundreds of millions of barrels of oil securely, withstand attacks, release oil quickly during disruptions, and have low maintenance over decades.
- The naive solution of external floating roof tanks (EFRTs) would require about 1,130 tanks and 45,000 acres (size of Washington, D.C.) for 714 million barrels, and they are vulnerable to attacks and fires, especially at the roof seal.
- The underground approach using steel-lined concrete tanks (like Red Hill) provides aerial protection but is extremely costly (hundreds of billions for scale), difficult to construct, and poses groundwater contamination risks, as seen in 2021 closures.
- The actual solution uses salt caverns, created by dissolving salt with water, in salt domes along the Gulf Coast. These caverns are secure due to salt's impermeability and self-sealing properties, and oil is extracted by pumping water in to displace it.
- Salt caverns are cost-effective (about $3.50 per barrel vs. $15-$18 for aboveground tanks) and strategically located near refineries and pipelines, but they require water and brine disposal, cavern enlargement over time, and ongoing maintenance.