OIL AND WATER: HOW PRODUCED WATER RECLAMATION IN THERMAL ENHANCED OIL RECOVERY MADE CALIFORNIA RESOURCES CORPORATION A NET WATER SUPPLIER

Two thirds of the 200 million barrels of oil produced annually in California is heavy oil – having an API gravity of less than 20 degrees. Heavy oil is often too viscous to recover at reservoir conditions, so operators use thermal enhanced oil recovery (TEOR) techniques such as steamfloods to heat the oil and improve its mobility. TEOR both uses and produces water, and includes the most efficient methods of recovery for heavy oil. Optimization, re-use and reclamation of water resources improve the operations and economics of many TEOR projects.

Lost Hills and Kern Front are two of California Resources Corporation’s (CRC) TEOR projects in the San Joaquin Valley. Thousands of acre-feet of water are used to produce the 10 - 14 deg API oil. At Lost Hills on the west side of the valley in the low lying, semi-arid back side of the Transverse Ranges, CRC targets the Pliocene Etchegoin and Tulare formations. Water is sourced from the productive zones and supplemented with purchased water from an irrigation canal. Produced water at Lost Hills is high in total dissolved solids (TDS) and is diluted, filtered and softened before it goes into steam generators to be re-injected into the reservoir. Water too high in TDS goes to disposal wells in a down dip position in the Etchegoin. At Kern Front on the east side of the valley in the foothills of the Sierra Nevada and adjacent to the Kern River, CRC relies entirely on recycled produced water from the Miocene Chanac and Pliocene Etchegoin formations, which are the productive intervals. Produced water is low TDS and is re-used to generate steam with minimal processing. Supplementation with surface water is unnecessary. Produced water not needed for steam is treated to strict Regional Water Quality Control Board standards and supplied to local water districts where it is blended with other sources of water then delivered to farmers for irrigation.

In 2015, CRC increased reclaimed water delivery to agriculture by 30%, to 8,100 ac-ft, far exceeding the total volume of fresh water used in our statewide operations. To expand our role as a net water supplier to agriculture, CRC continues to pursue opportunities to conserve fresh water and maximize the use of recycled and reclaimed produced water for beneficial use.