Reducing the impact of hurricane variability and change on the Offshore Energy Community in the Gulf of Mexico

Hurricane variability and change on climate time scales has considerable implications for the offshore energy industry in the Gulf of Mexico. According to a recent NOAA synthesis and analysis report (CCSP 2008), global warming will likely cause fewer but more severe hurricanes in the North Atlantic, the primary source of Gulf hurricanes. If true, this raises the possibility that new coastal and offshore facilities with design lives of many decades are being underdesigned, and that older facilities may need structural or operational modification in order to maintain presently accepted risk levels. Most of these impacts could be mitigated with proper planning provided we know far enough in advance.

As the NOAA synthesis report makes clear, the case for increasing severity is by no means overwhelming. Many uncertainties remain concerning the accuracy of the historical record and the numerical models. To narrow these uncertainties, a consortium from the oil industry and DOE has been working with NCAR to investigate the effect of global warming on hurricane activity for the next 50 years with a combination of statistical climate model downscaling and time-slice decadal hurricane predictions using the NCAR Nested Regional Climate Model. The results of that modeling are reported in several other papers to appear in this Conference.

In our study, we report on the impacts of these findings for the offshore energy industry. These fall into two broad categories: extremes and operation. Extremes like the 100-yr significant wave height are used to design most new facilities and changes of order 10% can affect the capital cost of a single deepwater structure by order $100 M. While less dramatic, changes in year-to-year hurricane activity can impact evacuation costs which sometimes run as high as order $500 M/yr for the Industry.