Coalinga Oil Field

The Coalinga Oil Field is a large oil field in western Fresno County, California, in the United States. It surrounds the town of Coalinga, about halfway between Los Angeles and San Francisco, to the west of Interstate 5, at the foot of the Diablo Range. Discovered in the late 19th century, it became active around 1890, and is now the eighth-largest oil field in California, with reserves totaling approximately 58Moilbbl, and over 1,600 active oil wells. The principal operators on the field, as of 2008, were Chevron Corp. (formerly Standard Oil of California or SoCal) and Aera Energy LLC.SettingCompared to many of the other California oil fields, Coalinga is large and spread out, but contains a few areas of concentrated development around the richer pools. The field has a rough semicircular shape open to the southeast, approximately twelve miles long by six across, with the town of Coalinga at the southwestern limit of the semicircle, and the agricultural Pleasant Valley inside. The oil field is mainly on the high ground around the valley, with the western part of the semicircle at the base of the Alcalde Hills, and the eastern part on the long and low Anticline Ridge, which separates Pleasant Valley and Coalinga from Interstate 5 and the main part of the San Joaquin Valley. The anticline in Anticline ridge continues to the southeast as the Guijarral Hills Oil Field and the Kettleman North Dome Oil Field. California State routes 33 and 198, which join together for the stretch through and north of Coalinga, cut across the Coalinga field and cross Anticline Ridge; along the route a passing traveler has a good view of oil field operations.