In recent years, higher domestic production of light, tight crude oil has led to a reduction in crude oil imports. Certain types of crude oil have been affected more than others; for example, the increased economic availability of domestic light, tight crude oil has virtually eliminated Gulf Coast imports of light crude oil. In the past year, Gulf Coast imports of medium crude oil have also fallen because of increased production from the Eagle Ford, Bakken, and Permian regions.
One of the key characteristics of crude oil is its density, measured by API gravity as established by the American Petroleum Institute. Less-dense liquids have higher API gravities. Crude oils with API gravities of 35 or above are considered light; 27 to 34 are medium; less than 27 are heavy.
From the first quarter of 2014 to the first quarter of 2015, medium-grade crude oil imports to Gulf Coast refineries decreased 45%, from 1.5 million barrels per day (b/d) to 0.8 million b/d. On the other hand, over that same period there was a 0.4 million b/d (22%) increase in imports to Gulf Coast refineries of heavy crude oil. Improved refining margins from processing additional volumes of heavy crude have resulted in a 3% increase in gross atmospheric distillation unit (ADU) throughput in the Gulf Coast region over this period, from 8.0 million b/d to 8.2 million b/d.
Almost all medium-grade crude oil imports are from Middle Eastern countries. Gulf Coast imports of medium crude oil from Saudi Arabia decreased by 52% from the first quarter of 2014 to the first quarter of 2015, from 0.9 million b/d to 0.4 million b/d. Similarly, Gulf Coast imports of medium crude oil from Kuwait decreased by 46% over this period, from 0.4 million b/d to 0.2 million b/d.