Earth Drops by 40 Feet in Kern County Oil Field

Nobody knows why, but a half-mile-long depression as deep as 40 feet in places has appeared in a Kern County oil field that is one of the state’s biggest producers.

“We’re continuing to monitor it to see if it’s going to grow any or not,” said Hal Bopp, a senior engineer with the state Division of Oil and Gas. “There are no plans to fill it in until we see what it is.”

The sagging earth, lined with numerous jagged cracks, was first noticed after a rainstorm Tuesday at a Shell Oil Co. production site in the South Belridge field along Highway 33.

State geologists said they don’t know what to think or do.

Mike Glinzak, a state oil and gas engineer, said the area has dropped by an inch to 40 feet in elevation. In several places there are holes that are 15 to 20 feet in diameter and 30 to 40 feet deep.

He said state geologists suspect that the cause of the hole is related to oil extraction or soil compaction caused by water. The least likely cause is earthquake fault activity, Glinzak said.

“It’s probably not the precursor to the Big One, as I’m sure a lot of people are thinking,” he said.

Other than a few oil pumps, no structures are threatened, but Shell has asked the state to erect a fence around the area to keep gawkers away.

As a precaution, Shell has closed 20 nearby wells, which produce a total of 250 barrels a day.

With the price of Kern’s heavy crude at $10 a barrel, the hole is costing at least $2,500 a day, not counting the expense of 24-hour security guards to keep people out of the area until the fence is built, production foreman Russ Howell said. “It’ll cost us some bucks,” he said.

The entire South Belridge field led the state in oil production in 1985, when it produced 55.1 million barrels, although the depression is in the least productive region, Glinzak said.