Offshore risers limitations

This chapter will first outline the conventional offshore riser repair techniques and their limitations which, in turn, provide the motivation for adoption of composite repair. A brief discussion about the application of FRPC in pipeline repair, its limitations, current practices, and material types will be given. A subsequent section provides information on the industrial design and safety standards used in designing and assessing the performance of offshore risers, corroded pipelines, and pipelines repaired with FRPC. The typical loading conditions of an offshore riser are also discussed so that the requirements of CRS can be understood. 

Conventional offshore riser repairs and their limitations... 

Limitations of the appiication of composite repair for offshore risers... 

ASME B31.4 (2006) Pipeline Transportation for Hydrocarbon Liquid and Other Liquids and ASME B31.8 (2003) Gas Transmission and Distribution Piping System are standards related to the design of pipelines which provide information on the stress and strain limits of industrial oil and gas pipelines. Although not specihcally intended for offshore risers, these standards provide a good foundation for pipeline design that in turn defines the requirements on the repair using FRPC materials. 

Semis are often used in water depths too deep for jack-ups. However, anehor handling and the length of the riser eventually impose a limit on the operating depth. Their stability makes them suitable vessels for hostile offshore environments. 

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