Thermo-Mechanical Analysis of Buried Heated Pipelines in the Shore Approach Area

Often in heated pipeline projects in the shore approach area the pipeline is buried with the disturbed soil but a partial natural recovering inevitably takes place once the trench is open. This condition may not be enough to ensure the required pipeline soil support for its design life. This peculiar condition of shallow and insufficient soil support may lead to an upheaval buckling. Hence, this paper intends to develop a numerical model to simulate the thermo-mechanical buckling phenomenon of buried heated pipelines in shore approach areas. Furthermore, a sensibility analysis adopting geometrical, physical and operational data is carried out for a particular Petrobras project. The in situ geophysical survey, geotechnical and oceanographic information are also taken into account. The influence of the sediment transport after opening the trench and required backfilling with a heavier soil is also addressed. This paper focuses on the challenges for the design and installation group, due to the burial requirements, in order to find a safe solution for the burying process by trenching and backfilling known methods.