While the U.S. has an abundance of domestic light oil resources, thanks to the shale revolution, the country's crude imports are focusing more on heavy oil, the U.S.' Energy Information Administration (EIA) said Friday.
Last year, more than 70 percent of the crude oil produced in the Lower 48 states (excluding Alaska and Hawaii) was light oil, while 90 percent of imported crude was heavy oil, the EIA said.
Light oil is characterized by type of crude having an API gravity above 35 degrees. Heavy crude has an API gravity below 35 degrees.
'To accommodate increasing U.S. production of light crude oil, refineries have adjusted their imports by reducing imports of light crudes,' the EIA said.
'The differences between domestic production and imports in this key oil characteristic could bring changes to petroleum refinery operations in the U.S.' it noted.
Domestic crude oil production has grown rapidly in recent years, due to light crude oil produced from tight oil, or known as shale, formations.
Around 90 percent of some 3 million barrels per day (mbpd) of average oil production growth in the U.S. between 2011 and 2014 consisted of light crude oil with an API gravity of 40 or above, the EIA estimates
During the same period, light crude oil imports of the U.S. fell from 1.7 million mbpd to 0.7 million mbpd.
'Most U.S. refineries are designed to run medium to heavy crude oil,' the administration said, pointing to the reason while some refineries have shifted their focus to importing heavy oil.
However, the EIA said there are technical solutions that the U.S. refineries can undertake in order to process more light crude if they see it more profitable.
'Depending on the prices of the different crude oils, the processing units that a refinery has, and the value of the resulting refined petroleum products, refineries will choose to process crude oils that optimize profit margins,' it said.
By Ovunc Kutlu in New York
Anadolu Agency
ovunc.kutlu@aa.com.tr