To Buckle or Not to Buckle - Best Practices for HP/HT Pipelines Lateral Buckling Design in Shallow Water

摘要

Mitigation of lateral buckling is one of the key design challenges for HP/HT subsea pipelines. Case studiesrnof lateral buckling designs in shallow water developments are used to examine the merits and shortcomingsrnof the different mitigation techniques. The case studies include both Greenfield and Brownfieldrndevelopments as well as existing pipelines in operation. The assessment covers the design methodology,rndesign challenges and methodology adopted to overcome those challenges as well as interaction withrnother pipeline design activities. Key factors such as technical feasibility, constructability and costeffectivenessrnof the different mitigation techniques are considered.rnThe different lateral buckling mitigation techniques described are generally applicable to subsearnpipelines in shallow water developments. The methods can be classified into two main approaches. Thernfirst is to prevent buckling and the second is to allow buckling to occur in a controlled manner. Hence,rna key decision for the designer is whether to aim for buckle prevention or buckle control i.e. to buckle orrnnot to buckle.rnThe assessment of the different techniques used for lateral buckling demonstrates that there is no ‘onernsize fits all’ solution. Unlike deep water applications where buckle prevention might be technicallyrnunfeasible or prohibitively expensive, the prevalence of shallow water in the Arabian Gulf region makesrnboth buckle prevention and buckle control generally feasible and cost effective solution. However, eachrnmitigation approach has its own pros and cons as well as limitations on its applicability and therefore thernmitigation approach should be determined on a case by case basis based on comprehensive technoeconomicrnassessment. Hence, understanding the merits and shortcomings of the different approaches isrnconsidered instrumental for proper selection of lateral buckling mitigation technique.rnThis paper provides guidance to the designer for the selection of mitigation approach throughrnconsolidation of the understanding of the merits and shortcomings of typical lateral buckling mitigationrntechniques in shallow water applications.