From the Summary: "The Strategic Petroleum Reserve (SPR), administered by the Department of Energy (DOE), has played a role in U.S. energy policy for over 40 years. Over that time, its primary focus has changed from its original intent as world oil market conditions have changed. Originally intended to offset the market power of cartels and prevent economic damage from oil supply disruption, it has become primarily a tool for combatting the fuel market effects of domestic natural disasters like hurricanes. Most recently, U.S. net imports of oil and petroleum products have decreased as a result of the increase in domestic oil production. Because of lower reliance on imports, some stakeholders see less need for an oil stockpile, and view the SPR more as a mechanism for providing funding for a wide variety of legislative purposes, ranging from health care, to highways, and general purpose revenues. Over this period, the SPR has expanded its potential usefulness to cover all of these purposes."
CRS Report for Congress, R45577
Congressional Research Service: https://crsreports.congress.gov/