简介:浮式生产储卸油系统(FPSO)是一种经济有效的浮式平台方案,特别是在缺乏足够的输油管道系统的深海领域.大多数FPSO是永久系泊的,即整个系统能够抵抗工作海域内的各种极值环境条件.目前,能够将FPSO与其系泊及立管系统快速解脱的装置已经设计并发展了.可解脱式FPSO的主要特点是可解脱性,并能避免一定的环境条件,如冰山,美国摩西哥湾的飓风,中国南海的台风.本文将针对深水海域可解脱式FPSO,提出其主要技术和工程分析与设计思路,评估可解脱式FPSO与永久式FPSO的优缺点,等等.可见可解脱式FPSO与永久式FPSO都是十分有效的浮式系统,并根据平台设计的安全性、技术、成本和运行要求,来决定选择何种系泊方式.
简介:Themostcriticalissueinthesteelcatenaryriserdesignistoevaluatethefatiguedamageinthetouchdownzoneaccurately.Appropriatemodelingoftheriser-soilresistanceinthetouchdownzonecanleadtosignificantcostreductionbyoptimizingdesign.Thispaperpresentsaplasticitymodelthatcanbeappliedtonumericallysimulateriser-soilinteractionandevaluatedynamicresponsesandthefatiguedamageofasteelcatenaryriserinthetouchdownzone.Utilizingthemodel,numerousriser-soilelementsareattachedtothesteelcatenaryriserfiniteelements,inwhicheachsimulateslocalfoundationrestraintalongtherisertouchdownzone.Theriser-soilinteractionplasticitymodelaccountsforthebehaviorwithinanallowablecombinedloadingsurface.Themodelwillberepresentedinthispaper,allowingsimplenumericalimplementation.Moreimportantly,itcanbeincorporatedwithinthestructuralanalysisofasteelcatenaryriserwiththefiniteelementmethod.Theapplicabilityofthemodelisinterpretedtheoreticallyandtheresultsareshownthroughapplicationtoanoffshore8.625″steelcatenaryriserexample.Thefatigueanalysisresultsofthelinerelasticriser-soilmodelarealsoshown.Accordingtothecomparisonresultsofthetwomodels,thefatiguelifeanalysisresultsoftheplasticityframeworkarereasonableandthehorizontaleffectsoftheriser-soilinteractioncanbeincluded.