Risk And Sensitivity Analysis Of Marine Riser

Marine riser is pipe connecting the operating platform and the bottom of the sea mineral deposit and it is an important part of a marine oil and gas system, which facilitates people to drilling, piping oil and gas, etc. But after it works in the sea for a long time, due to environmental disturbing, corrosion, pipe material failure and construction quality etc, the marine riser would be damaged and failure, this will result in explosion, poisoning, fire and other accidents, even great economic losses, casualties and environmental pollution. In recent years, marine riser failure accidents are increasing both at home and abroad, thus it is significance to investigate the risk factors for marine riser, to make sure possibility and ponderance of marine riser failure and evaluate its sensitivity, so as to take the corresponding protective measures. In this paper, many marine riser risk factors in service are analyzed and the riser risk factor hierarchical structure is modeled, the weight of each riser risk factor is evaluated by the improved fuzzy analytic hierarchy process (AHP) method, the different level and importance of all risks are demonstrate and its sensitivity is judged, protective measures are proposed to take according to the practice. The main context is as follows:At first, the corresponding data materials is collected, many marine riser risk factors are concluded by comparing with accident statistics of both at home and abroad, including:pipeline design and construction quality, natural environment, corrosion, third party damage, severe slugging closure.Second, the riser risk factor hierarchical structure is modeled, the weight of each riser risk factor is evaluated by the improved fuzzy analytic hierarchy process (AHP) method, while operation process of the improved fuzzy AHP was programmed and calculated by Matlab software, the different level and importance of all risks are demonstrate, protective measures are proposed to take according to the practice.Third, combined with the weight of the risk factors, the degree of importance and the sensitivity of each risk factor are determined.Finally, the main factors affecting the normal operation of the riser and riser system weaknesses are identified from both risk analysis and sensitivity riser analysis, combined with the actual operation of the riser, better protection and management measures are proposed to take. These results provide a theoretical reference for the maintenance, management and reinforcement of the marine riser.