Stress Analysis of Underwater Pipeline for Irregular Seabed Topography Using CAESAR II

• Main Author: Nurul Alia binti Mohd Anuar, Nurul Alia
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi Petronas 2011
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://utpedia.utp.edu.my/2694/1/DISSERTATION_FYP2_NAMA.pdf; http://utpedia.utp.edu.my/2694/

Offshore oil and gas pipelines are being subjected to deeper water depths, more extreme environmental conditions, and harsher operating requirements than ever before. Given these conditions, free spanning pipelines are becoming more common and are often unavoidable during pipeline installation. Free spans occur as a result of irregular seafloor topography at installation or during pipeline operation as a result of vibration and scour. A linear-elastic finite element model is applied to the solution of stress analysis problems involving submarine pipelines freely resting upon irregular seabed profiles. This report describes a finite element (FE) modelling procedure and parametric study leading to the investigation of stress distribution and deformation subjected on pipeline. The objective of this project is to model underwater pipeline using pipe stress analysis software, CAESAR II. The pipeline will be examined on various conditions according to the geometry of the seabed. The input or load cases of the pipeline system are ocean current and wave. The FE analyses are carried out for both the fully fixed and simply supported pipes, which form the two extreme conditions of pipelines under service conditions. Expected result is that the stress of the pipelines should not exceed the maximum allowable stress set by the regulations.