The U.S. Energy Information Administration (EIA) estimates that global spare crude oil production capacity averaged about 2.4 million barrels per day (bbl/d) during the first quarter of 2012, down about 1.3 million bbl/d from the same period in 2011 (see chart above). The world's spare crude oil production capacity is held by member countries of the Organization of the Petroleum Exporting Countries (OPEC). Spare capacity can serve as a buffer against oil market disruptions, and it gives OPEC additional political and economic influence in world markets. There is little or no spare capacity outside of the OPEC member countries.
Spare crude oil production capacity is now less than 3% of total world crude oil consumption—the lowest proportion since the fourth quarter of 2008—based on EIA estimates.
Spare crude oil production capacity is an important indicator of producers' ability to respond to potential disruptions; consequently, low spare oil production capacity tends to be associated with high oil prices and high oil price volatility. Similarly, rising spare capacity tends to be associated with falling oil prices and reduced volatility. However, spare capacity must also be considered in the context of a number of other market factors that can drive crude oil prices, such as global supply, demand, and inventory levels.
EIA defines spare crude oil production capacity as potential oil production that could be brought online within 30 days and sustained for at least 90 days, consistent with sound business practices. This does not include oil production increases that could not be sustained without degrading the future production capacity of a field.