This paper shall discuss in detail the effects that elevated temperatures can have upon traditional and new power cable materials when utilised in deep water umbilical applications; typical to Gulf of Mexico, West Africa and Brazil. In particular, the paper shall discuss current and future applications such as subsea processing and the impact these applications have upon the operational temperatures of power cable materials. FEA shall be presented and used to quantify the increase in temperature experienced by the power cables whist operated within a typical future subsea processing field. The particular system modelled utilises an aluminium power umbilical to operate subsea processing systems for development of long offset, deepwater offshore oil reservoirs. Current industry standards applicable for the design and manufacture of umbilical systems, such as ISO 13628-5, do not give sufficient guidance on the utilisation of power cable materials and the potential risks associated with increased temperature. To address this deficiency, tests have been performed to assess the effects upon the mechanical properties of both copper and aluminium power cables at component level and shall be presented within this paper. Focus has been placed upon the tensile, creep and fatigue properties. Using this data, guidance is given to potential de-rating methods and mitigations in order to reduce the risks to the umbilical. To demonstrate the impact of this guidance a typical case study is used and the impact of increased temperature has been quantified for the complete umbilical system.
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