A power outage at a steam plant at the Royal Dutch Shell (RDSA) Deer Park complex in Texas has disrupted production at the oil refinery, the company said Monday morning.

"We are working to resolve the situation as soon as possible, but anticipate we will not achieve normal rates for several days," Shell spokeswoman Emily Oberton said in a statement.

The steam plant, which is operated by Calpine (CPN), has not been restarted, Oberston said. The outage has also cause a majority of the chemical plant to shut down, she said.

The refinery has the capacity to process up to 329,800 barrels a day.

The refinery portion of the complex is a joint venture with Petroleos Mexicanos, or Pemex.

-By Susan Daker, Dow Jones Newswires; (713) 547-9208; susan.daker@dowjones.com