Critical Local Buckling Conditions for Deepwater Pipelines

摘要: In many deepwater pipeline applications, a clear understanding of pipe local buckling behaviour due to excessive bending and/or external pressure is required adequately design subsea systems an acceptable degree risk. With ultra-deepwater pipelines being considered for water depths nearly 3000 m, collapse, in instances, will govern design. For example, loads imposed on the near seabed (sagbend region) during installation reduce resistance pipeline, and this case influence (and generally govern) final selection appropriate wall thickness. To date, deepest operating have been laid using J-lay method, where departs lay vessel near-vertical orientation, only condition resulting from touchdown point sagbend. More recently, however, S-lay method 2800 m. During S-lay, originates horizontal bends around stinger located at stern or bow vessel, then orientation. Thus, installed experiences (overbend region), followed by combined sagbend region. view these loading conditions, analytical work was performed better understand thick-walled linepipe bending, collapse. Variables evaluations include material properties, geometric thermal treatment, definition critical strain, imperfections such as ovality girth weld offset. Presented finite element analysis (FEA) model developed perform assessments, validation model, results analyses correlations experimental data.Copyright © 2006 ASME