Chevron Corp. (CVX) is working to contain a mixture of steam and oil after a blowout yesterday at its Cymric field in California’s San Joaquin Valley.

The discharge took place at about 10:30 a.m., Russell Johnson, a Houston-based spokesman for Chevron, said in an e- mail late yesterday. Crews are on the scene working to stop the flow and the fluids being discharged are being contained, he said. No one was injured.

Johnson didn’t say how much oil was spilled. The Cymric field produces mostly heavy crude, which is forced out of the ground using steam.

To contact the reporter on this story: Gene Laverty in Calgary at glaverty@bloomberg.net

To contact the editor responsible for this story: Bill Banker at bbanker@bloomberg.net