Iran’s oil and gas industry is vital to its economy and government. Oil export revenues have accounted for more than 24 percent of Iran’s gross domestic product and between 50 and 76 percent of the Iranian government’s revenues in recent years. Iran has the world’s third largest oil reserves and second largest gas reserves, according to the Congressional Research Service (CRS), and is the world’s fourth largest producer of crude oil, according to the Central Intelligence Agency (CIA) World Factbook. However, Iran has not reached peak crude oil production levels since 1978, does not produce sufficient natural gas for domestic use, and lacks the refining capacity to meet domestic demand for gasoline, according to the Department of Energy (DOE) and IHS Global Insight.