Chevron Corp. reported Monday a recent flaring event at its refinery in Richmond, Calif., that was caused by an operational disruption.

"A plant upset resulted in flaring, causing the release of SO2 (sulfur dioxide) of greater than 500 pounds," the refinery said in a statement to the California Emergency Management Agency.

The flaring occurred Saturday and the release of gases has since stopped, according to the refinery.

The 250,000 barrel-a-day refinery is located just north of Oakland.

Write to Dan Molinski at dan.molinski@wsj.com

(END) Dow Jones Newswires

January 09, 2017 17:55 ET (22:55 GMT)Copyright (c) 2017 Dow Jones & Company, Inc.