Ask most Americans which was worse, Hurricane Katrina or Rita, and the nightmare of a flooded New Orleans prompts one answer -- Katrina. But from the standpoint of oil refining, Hurricane Rita caused more than twice the havoc and continues to significantly hinder U.S. oil production, said Ron Chittim, a senior associate with the American Petroleum Institute.
As of mid-October, 20 percent of the nation's refinery capacity is down or is restarting, Chittim said. Of that, 15 percent can be attributed to Rita while only five percent is Katrina related.
"There were a lot more refineries -- big ones -- affected by Rita," Chittim said. "They may not have had quite as extensive water damage as the ones closer to New Orleans, but if you look at the overall impact Rita was worse."
Of the refineries damaged by Katrina, three in Louisiana remain down while another in Mississippi is in the process of restarting. As the result of Rita, two refineries in the Beaumont-Port Arthur region remain shut down while another six located in Houston, Beaumont-Port Arthur and Lake Charles, LA, are either restarting or operating at reduced levels.
The one Houston refinery has been shut down since an explosion in March that killed 15 people. The company involved recently announced that operations would remain suspended until changes agreed to in a settlement with the U.S. Occupational Safety and Health Administration are implemented.
According to the Association of Oil Pipelines, almost all pipelines are operational though some are moving less crude oil and product than before the hurricanes.
More of the affected refineries survived the hurricanes with only moderate water and wind damage, Chittim said.
"The units in a refinery are huge," Chittim said. "They don't blow over. Interestingly enough, the cooling water towers did tend to get some damage. They are high profile, bulky pieces of equipment often supported by a wooden substructure. So there were several reports following Rita where cooling water towers were damaged."
Storage tanks have not proven as vulnerable as originally feared, he said.
"There was some damage to tanks," Chittim said. "However, when you think of all the thousands of tanks at refineries and terminals, I'm not surprised there were a couple. It's not quite clear yet what caused the damage. The wind may have been strong enough to lift the tanks off their foundations. I suspect that the fuller the tank the better it withstood the high winds."
Although secondary containment caught most of the spillage from damaged tanks, the containment was sometimes compromised by the magnitude of the storm surge, he said.
More than damage to the refineries, the factor holding up renewed production has been electrical power, Chittim said.
"Refineries are, by and large, operated by electricity," he said. "The power companies have made it a priority to try and restore that power as soon as possible."
In Texas alone, nearly 10,000 Southeast Texas Entergy customers remained without electric power four weeks following Hurricane Rita. At the peak of the damage resulting from the storm, about 286,000 customers were without power. All refineries affected by the hurricanes now have partial or full power.
"Assessment teams at the plants have to look at whether their has been water damage to pumps, compressors, motors, heat exchangers, instrumentation and control systems," Chittim told Industrial Fire World. "Instrumentation is particularly important because all modern refineries are run by computer now."
Even under ideal conditions, restarting a refinery calls for caution, he said.
"There is always risk involved in running a refinery," Chittim said. "You just have to manage that risk a bit differently during a startup. Often times you'll have more personnel on site. That means you'll have more people around watching the gauges than you would on just a normal operation. The plant may have to revamp its usual startup procedures in keeping with the hurricane response situation."
Added to that special concern is the fact that many refineries also have associated petrochemical operations such as plastics and olefin, a feedstock for the petrochemical industry.
"So you've got this huge amount of equipment that needs to be brought back on line," Chittim said. "It has to be done in an orderly and staged process that can take three to five days, depending on the size of the plant. During that period everything has to be closely monitored to make sure its done safely and smoothly."
That the refineries had sufficient time before the storm for a careful, orderly shut down aids in the process immensely, he said.
"The refineries had ample warning that Rita was headed for the Houston-Galveston area," Chittim said. "You can do a shut down in a day if you have to but you would normally like to do it in a little more staggered manner extended over two days. The refineries were able to go through an orderly shutdown.
"It makes it easier when you do come back to start up again because all your piping is clear, you've shut down your units the way they're supposed to be shut down so you don't have a lot of residue. When you make the decision to restart that should make it a lot easier and quicker." o