Volume of US Petroleum Reserves: "The standard unit to measure crude oil is a barrel (bbl). One barrel is equal to 159 liters. The volume of crude oil reserves worldwide is estimated at 160 trillion liters, of which some 4 trillion are to be found in the United States. By far, the majority of petroleum reserves (67%) are to be found in the Middle East Interesting to note is the fact that though the United States is the second largest producer, and by far the largest consumer of oil, it holds only 2.2 percent of the world's proven oil reserves. "
