U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2012–3120 

Revised February 2013

U

Remaining Recoverable Petroleum in Ten Giant Oil Fields of 

the Los Angeles Basin, Southern California

sing a probabilistic geologybased methodology, a team of 

U.S. Geological Survey (USGS) 

scientists recently assessed the 

remaining recoverable oil in 

10 oil fields of the Los Angeles 

Basin in southern California. The 

results of the assessment suggest 

that between 1.4 and 5.6 billion 

barrels of additional oil could be 

recovered from those fields with 

existing technology.

The Los Angeles Basin is a deep structural feature that began forming near the 

margin of the North American and Pacific 

Plates about 7 million years ago, during 

Late Miocene time (Wright 1991). The 

basin is bounded on the northwest by the 

Santa Monica Mountains, on the southeast 

by the San Joaquin Hills, on the east by the 

Puente Hills, and on the west by the Palos 

Verdes Peninsula. The basin’s small areal 

extent, prolific source rocks, thick sandstone reservoirs, and large anticlinal traps 

constitute a nearly ideal petroleum system. 

As a result, the Los Angeles Basin has one 

of the highest concentrations of crude oil in 

the world. Sixty-eight oil fields have been 

named in an area of about 450 square miles, 

including 10 accumulations that each contain more than 1 billion barrels of oil. One 

of these, Wilmington-Belmont, is the fourth 

largest oil field in the United States. 

Development of the oil fields during the 

twentieth century went hand in hand with 

rapid population growth and extensive 

urbanization of the Los Angeles Basin. 

Competing land use practices and evolving 

community priorities have constrained petroleum development throughout the history 

of the basin. In spite of abundant in-place 

resources and famously high local demand 

for refined petroleum products, recovery 

efficiency remains low and basinwide production continues to fall. Many small to 

medium-size oil fields have already been 

shut-in or abandoned, and recovery of oil 

from larger fields is increasingly restricted 

by State, County, and local policies and by 

competing commercial interests.

A team of U.S. Geological Survey 

(USGS) scientists has assessed the remaining recoverable oil in the 10 giant oil fields 

in the Los Angeles Basin using a probabilistic geology-based methodology (Klett 

and others, 2011) and reserves and production data from the California Division 

of Oil, Gas, and Geothermal Resources 

(2007). The team analyzed the geology 

of each field and reviewed its engineeringdevelopment history. Probability distributions for original oil in place (OOIP) were 

estimated for each field, and the fraction 

of the OOIP already developed was calculated. The probable range of maximum 

potential recovery efficiency (REmax) was 

evaluated on the basis of recovery efficiencies that have been modeled in engineering 

studies, achieved in similar reservoirs elsewhere, or indicated by laboratory results 

reported in technical literature. Probability 

distributions of OOIP and REmax were 

combined in a Monte Carlo simulation to 

estimate remaining recoverable oil. 

On the basis of this assessment of 

remaining oil in place and potential recovery efficiency, between 1.4 and 5.6 

billion barrels of additional recoverable 

oil are estimated to remain in the 10 

analyzed fields, with a mean estimate 

of approximately 3.2 billion barrels. 

Substantial recovery of these resources 

would require field redevelopment and 

unrestricted application of current bestpractice technology, including improved 

imaging and widespread application of 

directional drilling, combined with extensive water, steam, and CO2

 floods. 

Beyond the resources in the fields assessed here, additional recoverable oil may 

also remain in the other 58 existing oil fields 

in the Los Angeles Basin, in yet-to-find conventional oil fields, and in unconventional 

resources in petroleum source rocks (shale 

oil). Given the highly urbanized condition 

of the Los Angeles Basin, unrestricted development is hard to envision. Nevertheless, 

significant petroleum resources could probably be developed if needed. 

Oil derricks and houses in central Los Angeles, 1905. USGS photo by Ralph Arnold.
Wilmington-Belmont

Torrance

Huntington

Beach

Brea-Olinda

Dominguez Hills

Long Beach

Seal Beach

Inglewood

Santa Fe

Springs

Richfield

San Joaquin

Hills

Palos

Verdes

Puente Hills

Santa Monica

 Mountains

0 5 10 MILES

0 5 10 KILOMETERS

 Map of the Los Angeles Basin, showing oil fields (outlined in red). Fields evaluated in this 

study are shaded green and labeled by name.

Field

Known 

recoverable 

oil (MMBO)

Estimated OOIP (MMBO) Estimated recovery efficiency 

(percent) Remaining recoverable oil (MMBO)

Minimum Median Maximum Minimum Mode Maximum F95 F50 F05 Mean

Brea-Olinda 431 1,200 1,600 2,400 35 40 45 81 209 407.6 221.9

Dominguez Hills 274 1,000 1,200 1,450 35 40 50 146 224 321.2 227.7

Huntington Beach 1,164 3,250 3,500 6,000 35 40 55 117.1 371.5 866.2 416.2

Inglewood 430 1,000 1,400 2,500 40 45 55 67.2 224.6 520.2 249.9

Long Beach 946 3,000 3,100 3,600 35 40 55 207.9 392.2 663.5 410.3

Richfield 206 800 1,000 2,400 26 30 45 48.2 134.5 356.5 158.7

Santa Fe Springs 634 2,100 2,378 2,700 30 35 40 96.7 197.5 308 199.6

Seal Beach 221 850 900 1,000 35 40 50 109.4 152.9 210 155.7

Torrance 232 900 1,000 2,000 35 40 55 127.8 207.7 394.3 226.7

Wilmington-Belmont 2,984 7,600 9,000 12,000 35 40 55 199.9 909.8 1,948.1 972.6

All evaluated fields 7,522 1,443 3,079 5,565 3,239

[Known recoverable oil is the sum of cumulative production and reported remaining reserves; mean estimates add to a total mean, but fractile values for individual fields 

are not additive; fractiles (nonadditive) for the entire group of fields are shown in the bottom row, highlighted in yellow. OOIP, original oil in place; MMBO, million barrels of oil. F95 denotes a 95-percent chance of at least the amount tabulated; F50 denotes a 50-percent chance; F05 denotes a 5-percent chance]

Table 1. Assessment results for volumes of remaining recoverable oil in selected oil fields of 

the Los Angeles Basin, California (technically recoverable resources). 

References Cited

California Division of Oil, Gas, and Geothermal 

Resources, 2007, 2006 annual report of the State 

Oil and Gas Supervisor: California Department of Conservation, Division of Oil, Gas, and 

Geothermal Resources, publication no. PR-06, 

276 p., accessed April 2, 2012, at http://www.

conservation.ca.gov/dog/pubs_stats/annual_

reports/Pages/annual_reports.aspx.

Klett, T.R., Attanasi, E.D., Charpentier, R.R., Cook, 

T.A., Freeman, P.S., Gautier, D.L., Le, P.A., 

Ryder, R.T., Schenk, C.J., Tennyson, M.E., 

and Verma, M.K., 2011, New U.S. Geological 

Survey method for the assessment of reserve 

growth: U.S. Geological Survey Scientific 

Investigations Report 2011-5163, 8 p., available 

at http://pubs.usgs.gov/sir/2011/5163/.

Wright, T.L., 1991, Structural geology and tectonic 

evolution of the Los Angeles Basin, California, in Biddle, K.T., ed., Active margin basins: 

American Association of Petroleum Geologists 

Memoir 52, p. 35-103.

Reserve Growth Assessment Team: Donald L. 

Gautier, Marilyn E. Tennyson, Troy A. Cook, 

Ronald R. Charpentier, and Timothy R. Klett

 Edited by Peter H. Stauffer

Graphic design by Judy Weathers

For more information, visit:

 USGS Energy Resources Program Web site,

http://energy.usgs.gov/

or contact:

Donald L Gautier (gautier@usgs.gov)

345 Middlefield Road

Menlo Park, California 94025

This Fact Sheet and any updates to it are available online

at http://pubs.usgs.gov/fs/2012/3120/