DOE TO DEEPEN CALIFORNIA'S DEEPEST WELL

The U.S. Department of Energy plans to deepen California's deepest well in an effort to prove deeper production in Elk Hills field, blanketed by Naval Petroleum Reserve No. 1. DOE's 934-029R well, in the western portion of the field, bottomed at 24,426 ft in 1987 after more than 2 years of drilling. That was 1,715 ft deeper than the previous state record.

April 26, 1993

2 min read

The U.S. Department of Energy plans to deepen California's deepest well in an effort to prove deeper production in Elk Hills field, blanketed by Naval Petroleum Reserve No. 1.

DOE's 934-029R well, in the western portion of the field, bottomed at 24,426 ft in 1987 after more than 2 years of drilling. That was 1,715 ft deeper than the previous state record.

DOE, with Bechtel Petroleum Operations as contract operator, will attempt to get upstructure on a zone that produced oil and gas at noncommercial rates, along with salt water, during tests in 1989. The program calls for plugging back to kick off from about 13,490 ft, building angle at 3/100 ft to about 27, and holding at that angle to 17,615 ft total depth. If evaluation shows commercial production, 7 3/4 in. liner will be run for completion.

Completing the well would give California its deepest production. Currently, deepest production is from Rio Viejo field, 25 miles southeast of Elk Hills field, where upper Miocene Stevens sands are productive at an average depth of 14,100 ft.

ORIGINAL WELL

The target pay of DOE's 934-029R was tested in cased hole in summer 1989, flowing at rates of as much as 151 b/d of 42 gravity oil and 1.4 MMcfd of gas through a 12/64 in. choke from 130 ft of perforations in a gross interval at 17,100-365 ft in what was described as Oligocene Oceanic sand.

Along with oil and gas, the well flowed salt water at increasing rates, leading to a decision to suspend operations pending reentry.

The well was drilled as the third in a three well exploratory program begun by DOE in the 1980s to evaluate deeper horizons in Elk Hills field. Most of the oil that enabled the field to reach the 1 billion bbl production mark last September has come from sands above 9,000 ft, with only a small amount proved below that depth and none produced commercially from below 12,000 ft.

En route to total depth, the record depth well logged bottomhole pressure of more than 18,000 psi and temperatures exceeding 430 F.