The Midway-Sunset Oil Field is a large oil field in Kern County, San Joaquin Valley, California in the United States. It is the largest known oilfield in California and also the largest oil field in the country by total oil in place (around 27 billion barrels of mostly heavy oil), though Alaska's Prudhoe Bay Oil Field and the East Texas Oil Field have larger total production values of over 13 billion barrels and 5.4 billion barrels respectively compared to Midway-Sunset which has produced nearly 4 billion barrels.[1][2][3][4]
The field was discovered in 1894, and through the end of 2023 had produced close to 4 billion barrels (640,000,000 m3) of oil. At the end of 2008 its estimated reserves amounted to approximately 532 million barrels (84,600,000 m3), 18% of California's estimated total.[5]