Royal Dutch Shell PLC (RDSA) said Thursday that its Deer Park, Texas, refinery will return to normal processing rates over the weekend following a power outage on Monday.

The hydrocracker and olefins units are continuing to startup Thursday, Shell spokeswoman Emily Oberton said in a statement.

The crude, catalytic cracker, coker and hydrotreater are operating at planned rates, Oberton said.

On Monday, a steam plant operated by Calpine Corp. (CPN) lost power, resulting in the disruption.

The refinery has a capacity to process up to 329,800 barrels of crude a day. It is a joint venture with Petroleos Mexicanos, or Pemex.

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