Kenneth P. Henderson¹

(1) California Department of Conservation, Sacramento, CA

ABSTRACT: Historical Oil Production in California

The history of oil production in California centers around large sedimentary basins in the southern half of the state. Those include the Ventura, Santa Maria, and Los Angeles Basins, both onshore and offshore, and most importantly, the basins in the San Joaquin Valley.

First to utilize crude oil were the California Indians, who gathered the oil from natural seeps. The Indians used some oil as they found it, and refined some for specialized purposes. Around the mid-1800s, settlers coming to the state began more extensive activities, digging for asphaltum in shallow pits near active seeps and chipping at outcropped ledges, mostly in the San Joaquin Valley.

In the 1860s, oil tunnels were dug into mountainous sediments of the Ventura Basin that successfully extracted large quantities of oil, and it was then the first oil wells were drilled. By the mid-1860s, the State had its first oil boom, thanks to mines, tunnels, and "wells".

In 1876, well Pico No. 4 was completed in the Ventura Basin, the first truly commercial oil well in the State. Over 123 years later, California has produced about 25 billion barrels of oil from over 300 fields, of which about 200 are active currently. Although most of the oil has come from Miocene and Pliocene reservoirs, the State's oil and gas reservoirs range in age from Pleistocene to Cretaceous.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado