Chapter 4. Learnings from the Performance of Fixed Steel Structures in Gulf of Mexico Hurricanes

Starting in 1992 with Hurricane Andrew, thousands of fixed steel structures located in the Gulf of Mexico were subjected to seven major hurricanes ending with Hurricane Ike in 2008. While most structures survived with little or no damage, hundreds of structures were severely damaged and over 250 structures were destroyed. Since all of the manned structures were evacuated in advance of the hurricanes and operations shut-in, there were no lives lost and no major environmental issues. The offshore structures industry responded with multiple comprehensive studies and updated guidance documents addressing everything from metocean conditions, jacket structures, topsides structures, drilling rigs and masts, pre- and post-hurricane planning and other associated issues. The efforts involved API, government regulators, academia as well as individual operator initiatives.

This paper discusses these hurricanes and structures, looking at the types of damage and destruction, including issues such as wave-in-deck (WID), and then what went right and what went wrong. Several types of above and below water repairs related to integrity management are discussed including how some repairs installed after the first few hurricanes performed in subsequent hurricanes. Comparisons between hindcast hurricane wave conditions are described including global metocean loading compared to structure performance (survived, damaged, destroyed). Associated updates to API guidance are discussed including ongoing efforts to update the code calibration work performed at that time to some of the latest findings on metocean loading.