Like some of the levees in New Orleans, much of the oil producing infrastructure in the Gulf of Mexico wasn’t built to withstand a hurricane as powerful as Katrina, according to a petroleum engineering expert at the University of Missouri-Rolla.
But it’s not the damage to production platforms and rigs in the Gulf of Mexico or damage to the refineries on the mainland that most worry Dr. Shari Dunn-Norman, an associate professor of geological and petroleum engineering at UMR. She’s concerned about the damage to the sub-sea pipelines that carry crude oil and natural gas from the gulf to the refineries.
“It seems likely that damage to the pipelines is extensive,” says Dunn-Norman, an expert on how pipelines react in extreme situations.
According to the UMR researcher, the sea floor of the delta region where the Mississippi River empties into the gulf is vulnerable to mud slides, especially during and after strong hurricanes that cause extreme currents. In an article set to appear in the October issue of the journal World Pipelines, Dunn-Norman presents a study – researched and written prior to Katrina – about the impact Hurricane Ivan had on the petroleum industry in 2004.
Hurricane Ivan, with sustained winds of 165 mph, blew through the Gulf Coast last year and damaged 102 pipelines, 21 due to mud slides on the ocean floor.
“Ivan impacted 10,000 miles of pipeline,” Dunn-Norman says. “It took four months to repair pipelines to refineries.”
Although assessments are still being completed, Dunn-Norman says it’s a good bet that Hurricane Katrina and its sustained winds in excess of 175 mph damaged more pipelines than Ivan, which made landfall near Mobile, Ala.
Oil and gas fields in the Gulf of Mexico produce 21 percent of the natural gas consumed in the United States and 30 percent of the crude oil. But Katrina could have been an even greater blow to the industry, according to Dunn-Norman, if more of the production facilities in the deeper waters of the gulf had been impacted.
“Deepwater drilling rigs and production facilities don’t rest on the sea floor like the shallow water facilities and pipelines,” says Dunn-Norman. “They employ technology to more or less float in place. These floating rigs can be moved to better locations in advance of a hurricane.”
In the shallow waters of the gulf, many of the fixed platforms and drilling rigs directly in the storm’s path were damaged and in some cases destroyed along with the pipelines, while a lot of the facilities in deeper water were spared. Approximately 3,900 conventional steel platforms are attached to the ocean floor in the shallow regions of the gulf. But more than half of the oil and gas harvested from the gulf comes from the 50 or so large facilities located in deeper regions.
“The 37 facilities in shallow water damaged or destroyed by Katrina account for about one percent of the nation’s natural gas and crude oil production,” Dunn-Norman says. “The four facilities that were lost in deep water accounted for 10 percent.”
Similar to the levee system in New Orleans, much of the petroleum industry’s infrastructure in the gulf wasn’t built to withstand Category 5 winds exceeding 155 mph. The Mars tension leg platform, which was decimated by Katrina, was designed to withstand hurricane force waves of 71 feet and winds of 140 mph, simultaneously, according to Dunn-Norman.
“Design standards must be balanced against costs and the size of the oil or gas reserves, Dunn-Norman says. “It costs 25 to 50 million to drill one well. A facility like Mars can cost $900 million or more. At the time Katrina struck, it produced 150,000 barrels of crude oil per day.”
In addition to the pipelines, platforms and refineries damaged or destroyed by Katrina, at least three natural gas facilities were extensively damaged. Natural gas prices had already doubled in the two months prior to the hurricane. According to Dunn-Norman, the same pipeline network that carries crude oil in the gulf includes many natural gas pipelines.
“Looking forward to winter, even if we get the pipelines fixed, we’re looking at sustained high prices for natural gas,” Dunn-Norman says.