| Popis: |
Reeling has been an attractive offshore installation method for rigid flowlines and steel catenary risers due to its fast speed, cost effectiveness and reliability. Over years of evolution, it has become a proven technology, and the understanding to the engineering fundamentals is greatly improved as well. Due to the reeling process, the pipeline is plastically deformed; residual stresses, pipe ovality, and pipe out of straightness are increased. The strength, fatigue, and fracture performance of the pipe and the girth weld have to be closely evaluated to insure the pipeline integrity during and after the installation. As part of the installation design, different types of analyses are generally carried out to demonstrate the reelability, and the pipeline responses against all limit states. However, the methods adopted by different contractors can vary greatly. In this paper, the engineering fundamentals of reeling process are reviewed. A few typical reeling analyses, both analytical and finite element based, are demonstrated with examples. The local buckling limit state criteria based on DNV-OS-F101 for different stages of reeling are also illustrated. |
