The Strategic Petroleum Reserve
The Strategic Petroleum Reserve is the world’s largest known emergency oil supply with a maximum capacity of 714 million barrels of crude oil. There are four sites along the Gulf of Mexico named Bryan Mound, Big Hill, West Hackberry, and Bayou Choctaw. In 1973, the Organization of Arab Petroleum Exporting Countries (OAPEC) imposed an oil embargo against the United States which caused a major supply shock and recession. In 1975, Gerald Ford established the Strategic Petroleum Reserve to protect the US from future supply shocks.
How the Storage Works
The emergency reserves are stored underground in salt caverns. The salt caverns are drilled in an area where there is a salt deposit. After drilling down to the salt deposit, water is pumped through pipes to dissolve a massive area of salt. Once the salt is dissolved, the brine is extracted back up to the surface and stored for future use. Now that the cavern has formed, crude oil can be stored. If oil needs to be extracted from the cavern, the brine is pumped back into the cavern and because the brine is denser than the oil, the oil rises to the top where it can be collected. This process of filling and extracting can be done repeatedly.
How the Oil is Used
The emergency supply of oil is owned by the United States and can be used at their discretion. Congress and the President can sell or buy more oil to help fund the government and they can authorize the oil to be used in emergency scenarios. The Strategic Petroleum Reserve helps to keep the United States oil supply stable and less reliant on foreign entities. The current inventory of oil is about 372 million barrels of oil which is around an 18-day supply, or a little more than half of the maximum inventory of 714 million barrels.