Valero Energy expects its 170,000-barrel-per-day refinery in Sunray, Texas, will be shut at least through the middle of the week, a spokeswoman said on Sunday.
About 40 operators were expected to enter the refinery, 60 miles north of Amarillo, Texas, on Sunday to begin removing partially refined products from units rapidly shut down following a Friday explosion, said Valero spokeswoman Mary Rose Brown.
The site of Friday's explosion may not be entered until at least midweek because of risk of reigniting a fire in a propane deasphalting unit that refines gunky, thick residual crude oil
into either gasoline feedstock or asphalt.
The propane deasphalting unit is near storage tanks that were at risk of explosion if flames came too close, leading to evacuation of refinery workers and shutdown of the plant.
"This is a highly sensitive situation and we're going to be dealing with this very judiciously," Brown said in a telephone interview.
A delay in entering the explosion site could slow investigations by the U.S. Occupational Safety and Health Administration and the U.S. Chemical Safety and Hazard Investigation Board, both of which have investigators at the refinery.
Spokesmen for both agencies were not immediately available to discuss the matter.
Removing partially refined products from rapidly shut equipment is the first step to return the units to a normal state of readiness for restarting refinery production.
There is no date for restarting the refinery, Brown said. She could only say for certain it would be midweek before the company could contemplate restarting.
Valero's Sunray refinery supplies gasoline and other motor fuels to Arizona, Colorado, north and west Texas. A shutdown could affect prices in markets as far away as Los Angeles, where refineries produce some of the gasoline going to Arizona.