Geo Gold Emmons: March 2017

Since I went to Thousand Oaks high school (1969) in Ventura County, California, I was able to enjoy surfing at the Ventura and LA beaches. On the drive to the beach at Rincon north of Ventura we would pass the Ventura oil field and the offshore drilling platforms. So I looked for some information on the oil field on the internet. My first look was on Google Earth.

Satellite image of the Ventura Oil Field (Source: Google Earth).

The Ventura oil field was discovered in 1919 by Shell Oil Company. The discovery well was drilled to a total depth of 3,498 feet. The oil is produced from depths of up to 12,000 feet. The field has produced nearly one billion barrels of oil through 2008. In 2009, the field was still producing oil from 423 wells. Wikipedia.org/wiki/Ventura_Oil_Field

The large, east-west Ventura anticline is the structure along with faults that controls the location of the pools of oil. The limbs of the fold dip steeply from 30 to 60 degrees. The upper reservoirs are in the Pico Formation (Plio-Pleistocene) and the lower reservoirs are in the Santa Margarita Formation. The underlying Monterey Formation (Miocene) is the source rock for the oil and gas. This formation is rich in organic matter. A total eight zones have produced oil; the named zones are one through eight based on their depth.

Photo of anticline looking westerly. The Pacific Ocean is in the background.
Source: Callan Bentley.
blogs.agu.org/mountainbeltway/2013/11/15/friday-fold-ventura-avenue-anticline/.

The Ventura Oil Feild poster by the City of Ventura, California.
http://www.cityofventura.net/files/file/comm-service/14-Oil.pdf

Old photographs of some of the oil fields of southern California from the first half of the 20th century. From the Mashable website: mashable.com/2015/12/06/oil-drilling-beaches/ Photographs compiled by Alex Q. Arbuckle, Retronaut, more are available on his website.