In 2012 California produced 197 million barrels of crude oil , out of the total 2,375 million barrels of oil produced in the U.S. California drilling operations .
Oil production are concentrated primarily in Kern County , San Joaquin Valley and the Los Angeles basin .
In 2012 California produced 197 million barrels of crude oil , out of the total 2,375 million barrels of oil produced in the U.S. California drilling operations and oil production are concentrated primarily in Kern County , San Joaquin Valley and the Los Angeles basin .