The risk analysis technique is applied to· those accidental scenarios associated with the external human offshore activities in the areas, outside platform safety zone, crossed by a pipeline. The interaction with ship anchors, dropped objects, sinking ships and fishing gears are discussed. Basic data and methodology for the frequency assessments are presented as well as Some consideration on the consequence assessment.
The term "Risk" encompasses considerations relevant to both expected frequency of accidental events and the relevant consequences. Design solutions and protection means can cope with most, but not all, of the possible negative occurrences during the life time of a pipeline. After the application of safety standards and rules, the residual possibility of accidental events needs to be assessed. The application of risk analysis techniques to the offshore pipeline design, and cost/benefit analysis, help the project team in the decision making relevant to the optimum design solutions. This paper deals with possible methods and means to be adopted for the identification of risks associated to offshore pipelines in operation, with particular concern to those risks induced by human activities along the pipeline route.
The risk analysis technique has been largely applied in offshore engineering. Potential Hazards: the hazardous conditions which could cause pipelines to fail can be schematically separated into two categories: natural and man- made. Natural are those caused by environmental and/or natural occurrences and disasters such as severe sea states, hurricanes, earthquake, bottom instability, etc. Mart-made hazards are those related to offshore activities, erroneous pipeline operating conditions and material deficiencies. In this paper, the attention is focused to man-made hazards relevant to third party offshore activities. These accidental scenarios are discussed in the following and the major aspects, relevant to· the frequency and consequence assessment, are identified.
