Static Analysis for Offshore Pipelay using software OrcaFlex: Development and Validation of a Model

This thesis presents a static analysis of offshore pipeline installation using the simulation software OrcaFlex. The study focuses on modeling the pipelaying process and assessing the mechanical response of the pipeline during deployment. To evaluate the reliability of OrcaFlex, the results obtained are systematically compared with those generated by the well-established OFFPIPE software. Previous projects have reported a misalignment between OrcaFlex and OFFPIPE results, particularly for deepwater S-lay installations. This discrepancy motivated the present research, which aims to identify the causes of these differences, propose corrective approaches, and test the validity of OrcaFlex outputs under challenging installation scenarios. To achieve this, a dedicated modeling framework was developed in OrcaFlex and benchmarked against existing OFFPIPE analyses. The comparative assessment highlights both similarities and discrepancies in the computed pipeline catenary configurations, stresses, and tension distributions. These outcomes provide valuable insights into the accuracy and robustness of the numerical models implemented in each software package, as well as the influence of modeling assumptions, boundary conditions, and input parameters on the predicted pipeline response. By clarifying the capabilities and limitations of OrcaFlex relative to OFFPIPE, this thesis contributes to improving the reliability of offshore pipelaying analysis. The findings support engineers and practitioners in selecting appropriate simulation tools, enhancing confidence in design calculations, and ultimately contributing to the optimization of offshore pipeline installation processes.