Evaluation of abandonment and recovery operation of steel lazy-wave riser in deepwater is presented in this paper.The calculation procedure includes two single continuous SLWR and cable segments, which are coupled tog...Evaluation of abandonment and recovery operation of steel lazy-wave riser in deepwater is presented in this paper.The calculation procedure includes two single continuous SLWR and cable segments, which are coupled together to form the overall mathematical model. Then the equilibrium equations of SLWR and cable are established based on minimum total potential energy principle. The coupled equations are discretized by the finite difference method and solved by Newton-Raphson technique in an iterative manner. The present method is validated by well-established commercial code OrcaFlex. Recovery methods by considering different ratios of vessel’s moving velocity to cable’s recovery velocity are evaluated to optimize the abandonment and recovery operation. In order to keep the tension more stable during the recovery process, the rate ratio before leaving the seabed is increased, and the rate ratio after leaving the seabed is reduced.展开更多
钢悬链立管J型铺设作业窗口是为了确定其正常铺管的环境条件,找到正常铺管和弃管作业的界限。本文以API RP 2RD立管规范许用应力法和semi-submersible半潜式铺管船的张紧能力为作业窗口综合校核准则,使用ORCAFLEX软件建立钢悬链立管J型...钢悬链立管J型铺设作业窗口是为了确定其正常铺管的环境条件,找到正常铺管和弃管作业的界限。本文以API RP 2RD立管规范许用应力法和semi-submersible半潜式铺管船的张紧能力为作业窗口综合校核准则,使用ORCAFLEX软件建立钢悬链立管J型铺设有限元模型,分析铺设过程中浪流相对方向、不同波浪方向下波高-周期、波浪-海流条件下的立管强度和产生的最大有效张力,以此确定钢悬链立管J型铺设作业窗口。结果表明,浪流同向时作业窗口最小;当海流大小一定且与波浪同向,波浪方向为180°,波浪周期在铺管船固有周期附近时作业窗口最小;铺设作业系统对于波浪的敏感性更强。同时,分析了J型铺设作业窗口的影响因素,除波浪、海流的影响外,铺管船和立管的特性也对作业窗口作用明显。在铺设系统设计以及铺管作业时,环境载荷、铺管船、和立管结构等方面是决定铺管作业窗口的核心因素。展开更多
阐述深水钢悬链立管安装中的弃管回收工艺,采用理论分析和数值分析相结合的方法,对深水钢悬链立管安装中的弃管回收进行分析。基于经典悬链线理论,编制钢悬链立管弃管回收分析软件SCRCOV,针对1 500 m水深和10 in SCR制定弃管回收方案,...阐述深水钢悬链立管安装中的弃管回收工艺,采用理论分析和数值分析相结合的方法,对深水钢悬链立管安装中的弃管回收进行分析。基于经典悬链线理论,编制钢悬链立管弃管回收分析软件SCRCOV,针对1 500 m水深和10 in SCR制定弃管回收方案,经商业软件ORCAFLEX验证,自编软件计算结果是准确的。展开更多
基金financially supported by the National Natural Science Foundation of China (Grant No.52271299)the Science Foundation of China University of Petroleum,Beijing (Grant No.2462020YXZZ046)。
文摘Evaluation of abandonment and recovery operation of steel lazy-wave riser in deepwater is presented in this paper.The calculation procedure includes two single continuous SLWR and cable segments, which are coupled together to form the overall mathematical model. Then the equilibrium equations of SLWR and cable are established based on minimum total potential energy principle. The coupled equations are discretized by the finite difference method and solved by Newton-Raphson technique in an iterative manner. The present method is validated by well-established commercial code OrcaFlex. Recovery methods by considering different ratios of vessel’s moving velocity to cable’s recovery velocity are evaluated to optimize the abandonment and recovery operation. In order to keep the tension more stable during the recovery process, the rate ratio before leaving the seabed is increased, and the rate ratio after leaving the seabed is reduced.
文摘钢悬链立管J型铺设作业窗口是为了确定其正常铺管的环境条件,找到正常铺管和弃管作业的界限。本文以API RP 2RD立管规范许用应力法和semi-submersible半潜式铺管船的张紧能力为作业窗口综合校核准则,使用ORCAFLEX软件建立钢悬链立管J型铺设有限元模型,分析铺设过程中浪流相对方向、不同波浪方向下波高-周期、波浪-海流条件下的立管强度和产生的最大有效张力,以此确定钢悬链立管J型铺设作业窗口。结果表明,浪流同向时作业窗口最小;当海流大小一定且与波浪同向,波浪方向为180°,波浪周期在铺管船固有周期附近时作业窗口最小;铺设作业系统对于波浪的敏感性更强。同时,分析了J型铺设作业窗口的影响因素,除波浪、海流的影响外,铺管船和立管的特性也对作业窗口作用明显。在铺设系统设计以及铺管作业时,环境载荷、铺管船、和立管结构等方面是决定铺管作业窗口的核心因素。
文摘阐述深水钢悬链立管安装中的弃管回收工艺,采用理论分析和数值分析相结合的方法,对深水钢悬链立管安装中的弃管回收进行分析。基于经典悬链线理论,编制钢悬链立管弃管回收分析软件SCRCOV,针对1 500 m水深和10 in SCR制定弃管回收方案,经商业软件ORCAFLEX验证,自编软件计算结果是准确的。
