By the OGJ Online Staff
WASHINGTON, DC, Mar. 28�The US Department of Energy said Tuesday a government-industry experiment has revived a central California lease and resulted in the production of more than 1 million bbl of oil once thought unrecoverable.
DOE said because of the project, oil is flowing from 100 privately funded wells nearby and millions of barrels more could be recovered from the Bakersfield area.
The project was on the Pru Fee lease, part of giant Midway-Sunset field 30 miles southwest of Bakersfield. The University of Utah, Aera Energy LLC, and ARCO Western Energy Co. conducted the test.
DOE said the 1 million bbl produced in the last 5 years is more than half as much oil as the property produced in all of its first 80 years of operation. Project sponsors predict that the advanced technologies ultimately will result in more than 4 million bbl of recovery.
The project was one of several in DOE�s Reservoir Class Oil Field Recovery Program. Begun in 1991, the program targeted geologic classes of US oil fields that were about to be abandoned.
The Pru Fee project in the Midway-Sunset field was selected in the third round of the program in 1995. DOE provided $2.2 million and the University of Utah and its industry partners spent $3.6 million.
The Pru lease in Midway-Sunset field came on production in 1906. By the late 1960s, operators were injecting steam to keep heavy oil flowing. The field was producing 300 b/d in 1972, but by 1985 dropped to less than 10 b/d and the lease was abandoned.
In the DOE-funded project, engineers created a detailed geologic profile of the reservoir and fed the data into computer programs that simulated how the reservoir would respond to various production strategies.
Initially, ARCO Western tried cyclic steam flooding, using an 8-acre section of the lease to alternately inject steam, then recover oil. Production dropped after two steam cycles. The research then turned to continuous steam injection, sending a steady flow of steam down one set of wells and recovering oil from others. Production increased to more than 1,500 b/d.
By early 1999, 37 new wells had been drilled on the lease. Aera Energy, which acquired the lease from ARCO, began applying the technologies to surrounding leases. So far, 54 new wells have been placed on production, the most recent at the Lilly lease, which is twice as large as Pru and could hold up to 10 million bbl of recoverable oil.
DOE�s National Petroleum Technology Office said applying the methods to only half the 26 currently shut-in Midway-Sunset properties could produce another 80 million bbl of oil.
