Sunday, August 26, 2012

Hurricane ISAAC and the Gulf Coast

The political world is waiting patiently for Tuesday, when the Republican National Convention is officially getting under way, after a postponement due to the nearby passage of what remains Tropical Storm ISAAC. The question that begins to arise, however, is as to whether the political news will be swamped by the consequences of ISAAC’s arrival.

Figure 1. The current prediction for the path of Tropical Storm ISAAC, as it skirts Florida, on its way to the Gulf Coast.(National Hurricane Center)

It has been some 7 years ago that the three hurricanes of 2005, DENNIS, KATRINA and RITA, did a number on Gulf oil production. We have, in the interim, perhaps become a little complacent about the impact of a major hurricane on Gulf oil production. It was DENNIS which did such damage to the Thunder Horse platform back in July of 2005, that it took several years to bring it back into operation. (video here ). DENNIS shut in some 1 mbd, but for only a short time.

Figure 2. The Thunder Horse platform after Hurricane DENNIS in July of 2005. (Youtube )

However it was followed by KATRINA and RITA, so that, between the three of them they covered not only the swath of the ocean that included most of the drilling platforms in the Gulf, but also, as they moved inland, a significant number of the refineries on which the nation has come to depend.

In the seven years since then, the lack of significant hurricane impact on the Continental United States has led to some complacency as to the vulnerability of the country to the hurricanes that have, from time immemorial, threatened these shores.

But it is worth just a quick reminder that the impact is not just seen in damage on shore, grievous though that may become. (I was on a survey team that was one of the early groups that went down the delta after KATRINA). Already platforms are being secured:
The Bureau of Safety and Environmental Enforcement says 39 production platforms and eight drilling rigs have been evacuated as of Sunday. That's about 6.5 percent of the 596 manned platforms and 10.5 percent of the 76 rigs operating in the Gulf of Mexico. . . . . . . The bureau says operators estimate that about 24 percent of the current daily oil production and 8 percent of natural gas production has been cut off.

The paths of the storms are somewhat different. KATRINA came in more directly from the south:

Figure 3. Path of KATRINA in 2005 (Central Florida Hurricane Center).

The path of ISAAC is currently anticipated to be more direct, as shown in Figure 1, but there are several things to bear in mind, as we move into this week.

Figure 4. Platforms along the Gulf of Mexico (FOX 4)

Firstly it was not only the platforms themselves that caused the problems in the United States after the hurricane season of 2005. There are a lot of refineries around the NOLA area that were damaged at the time, and which have not moved since.

Figure 5. Refineries around New Orleans in the region of the KATRINA hurricane track.

Hopefully between then and now the relevant refinery will have got all the switchgear that gave them problems back then out of the basement and into a less flood-threatened location.

As far as the people that live in the region are concerned, there are two additional worries. The first is that there is some thought that the hurricane may strengthen beyond a level 2, and KATRINA was only at a level 3 when it hit in 2005. The second is the direction in which the storm is approaching. While KATRINA had the full length of the delta over which to lose power, if ISAAC swings in from the East then it will pose a greater threat to the levees because it will impact Lake Ponchartrain.
If the storm tracks west of New Orleans, a storm surge into Lake Ponchartrain could push water against the city’s still-fragile levee system. If the storm makes landfall east of New Orleans, northerly winds on the west side of the storm could still create wave and water problems for the Crescent City. A landfall east of New Orleans could also bring a devastating storm surge onto the Alabama-MIssissippi coast.
. As a precaution rigs and platforms have been put into a protective posture, which has reduced daily oil production by 24% and natural gas production by 8%.

Until the full nature of the threat develops, however, it is thought that the refinery fire in Venezuela may have greater impact, although it is being reported that the damage there was constrained to just two storage tanks. (Not that this is as big a concern to the United States as it used to be:
In the first five months of 2012, the United States imported just over 50,000 bpd of fuel from Venezuela, down from nearly 290,000 bpd in 2005, according to data from the U.S. Energy Information Administration.
And for the people of New Orleans and particularly those in the ninth ward, I hope that this time they have not dredged next to the levees, nor have they left any of the barges less than totally secured.

And, lest the Democratic Party start to feel too superior, there are rumors of another Tropical Depression that might make it more interesting in Charlotte, in early September.

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