|Tiratoo, E.N. Oilfields of the World. England: Scientific Press, Ltd, 1984: 244.||"US crude oil production in 1970: 3,517.5 MM brl"||559 billion liters|
|Johnson, Otto, ed. 1997 Almanac. Massachusetts: Houghton Mifflin, 1997: 141.||"US Crude oil petroleum production in 1992: 363 million metric tons"||398 billion liters|
|Bhattacharye, Amindya K. The Myth of Petropower. New York: Heath, 1977.||"US crude oil production in 1973: 9,189 (thousand barrels per day)"||533 billion liters|
|World Statististics in Brief: Department of Economic and Social Affairs Statistical office. Statistical Papers. Series V, No. 1 New York: United Nations, 1976: 30||"US production of crude petroleum in 1973: 454.2 million metric tons"||498 billion liters|
|Energy Information Administration.||"US crude oil and lease condensate production in 1995: 6.53 million barrels per day"||379 billion liters|
Petroleum, also known as crude oil, is one of the most valuable resources in the world. The United States currently has approximately 26 billion barrels in the reserves. Barrel is the standard unit to measure crude oil and most petroleum products. One barrel is equal to 159 L. The volume of petroleum is sometimes expressed in metric tons. 0.145 metric tons is equivalent to one barrel, or 159 L.
As the United States became more industrialized, the need for oil intensified, calling for a greater production in petroleum. Peak production of this material came about in 1970. However, since the 1970s, heightened concern for the environment has lead the US Department of Energy to limit the rate of consumption. This effort of preserving our natural resources and conserving energy has resulted in a steady decline of US petroleum production in proportion to the world production of petroleum. In 1920, the US generated over 63% of the aggregate world output of crude oil. In 1982, the US constituted only 16%, and in 1996, only 2.5% of the total yield. What is interesting is that we are currently importing more crude oil than we are producing (420 billion liters as compared to 379 billion liters).
Haiyan Xie -- 1997