The US Geological Survey (USGS) has assessed that the Los Angeles Basin holds 61 million bbl of technically recoverable oil and 240 Bcf of gas still undiscovered. Since the 1880s, the region has produced or discovered 9 billion bbl of oil, equal to 14 months of current US consumption.
The Los Angeles Basin includes the coastal plain and waters of Los Angeles and East LA north to the Santa Monica Mountains, east to Angeles National Forest and the foothills of the Sierra Nevadas, and east and south into much of Orange County (Fig. 1).
According to USGS, four assessment units were evaluated—one for conventional oil, two for shale oil, and one for shale gas—with findings indicating that, after nearly 150 years of exploration, few undiscovered resources remain in the basin.
USGS oil and gas assessments began 50 years ago in response to an oil embargo, emphasizing the need to understand resource availability. These assessments continue to provide critical data for US energy policy and resource management. While these basins have been productive historically, the latest assessment suggests that the remaining undiscovered resources are limited compared with past production levels.