Coupled Dynamic and Static Analysis of Typhoon TLP Accident During Extreme Environmental Conditions

An important path to reviewing technology is through failure investigation, which enables understanding of appropriate levels of safety and assurance of design criteria. In the occurrence of extreme environmental conditions in which most units respond well or at least satisfactorily, the assessment of exception cases can be taken as a good starting point for the failure investigation mentioned above. Hence, especially on account of hurricanes Rita and Katrina, the 2005 hurricane season, which had a notable impact on offshore industry at Gulf of Mexico region, can be taken as a promising scenario to assess the losses and bring out cases to be more carefully appraised. It is the case of the TLP Typhoon found upside down after the passage of Rita. Being the only unit located at a significant water depth which followed recent project standards, the case naturally came to the fore. This paper addresses an investigative analysis held out in order to establish and analyze the possible causes that resulted on the capsizing of the referred unit. The investigation focuses on two major paths which were selected as being the most probable and also had feasibility to be carried out — one that analyzes a possible lack of displacement due to the passage of a hurricane wave and the consequent loss of stability of the TLP and the other, concentrated on a dynamic analysis of the unit under the impact of the hurricane metocean conditions. This second analysis focuses on obtaining the tension on the tethers stating if either they suffered excessive loads causing them to break or lack of it, causing compression and possible buckling.