A letter report issued by the Government Accountability Office with an abstract that begins "Congress authorized the Strategic Petroleum Reserve (SPR), operated by the Department of Energy (DOE), to release oil to the market during supply disruptions and protect the U.S. economy from damage. The reserve can store up to 727 million barrels of crude oil, and currently contains enough oil to offset 59 days of U.S. oil imports. GAO answered the following questions: (1) What factors do experts recommend be considered when filling and using the SPR? (2) To what extent can the SPR protect the U.S. economy from damage during oil supply disruptions? (3) Under what circumstances would an SPR larger than its current size be warranted? As part of this study, GAO developed oil supply disruption scenarios, used models to estimate potential economic harm, and convened 13 experts in conjunction with the National Academy of Sciences."