Management of Reclaimed Produced Water in California Enhanced with the Expanded U.S. Geological Survey Produced Waters Geochemical Database

Abstract:

In California, in 2014, every barrel of oil produced also produced 16 barrels of water. Approximately 3.2 billion barrels of water were co-produced with California oil in 2014. Half of California’s produced water is generally used for steam and water injection for enhanced oil recovery. The other half (~215,000 acre-feet of water) is available for potential reuse. Concerns about the severe drought, groundwater depletion, and contamination have prompted petroleum operators and water districts to examine the recycling of produced water. Knowledge of the geochemistry of produced waters is valuable in determining the feasibility of produced water reuse. Water with low salinity can be reclaimed for use outside of the petroleum industry (e.g. irrigation, municipal uses, and industrial operations). Since a great proportion of California petroleum wells have produced water with relatively low salinity (generally 10,000-40,000 mg/L TDS), reclaiming produced water could be important as a drought mitigation strategy, especially in the parched southern San Joaquin Valley with many oil fields.

The USGS Produced Waters Geochemical Database, available at http://eerscmap.usgs.gov/pwapp, will facilitate studies on the management of produced water for reclamation in California. Expanding on the USGS 2002 database, we have more accurately located California wells. We have added new data for 300 wells in the Sacramento Valley, San Joaquin Valley and the Los Angeles Basin for a total of ~ 1100 wells in California. In addition to the existing (2002) geochemical analyses of major ions and total dissolved solids, the new data also include geochemical analyses of minor ions and stable isotopes. We have added an interactive web map application which allows the user to filter data on chosen fields (e.g. TDS < 35,000 mg/L). Using the web map application as well as more in-depth investigation on the full data set can provide critical insight for better management of produced waters in water-constrained California.