FPSO系泊索疲劳寿命影响因素分析

Influence factor analysis of FPSO mooring rope fatigue life

以南海某石油开采区块螺旋股钢丝绳为例,采用Miner线性损伤累积理论和螺旋股的S-N曲线对螺旋股钢丝绳系泊索的疲劳寿命进行预测。给出FPSO系泊索疲劳寿命影响因素:(1)腐蚀是影响系泊索轴向拉伸疲劳寿命的主要外在因素。钢丝绳在海水中的疲劳寿命比在空气中降低82%。(2)钢丝绳设计水平、制造质量、盘条质量是影响系泊索疲劳寿命的内在因素。在钢丝绳设计、制造过程中应注意保证钢丝绳的刚度、自重、最小破断力达到初始设计要求。可以采用钢丝表面镀锌、挤塑护套、良好的润滑/阻滞物、牺牲阳极及外加电流系统等降低钢丝绳的腐蚀速度,提高钢丝绳的疲劳寿命。

To take spiral strand wire rope in south China sea some oil exploration block as example,the fatigue life of helical strand wire rope mooring rope is predicated by adopting Miner linear cumulative damage theory and spiral strand S- N curve. The influence factors of FPSO mooring rope fatigue life are given as follows:( 1) corrosion is main outer factor influencing mooring rope axial tensile fatigue life,the fatigue life of wire rope in sea is lower than that of air about 82%.( 2) the design and production quality of wire rope,wire rope quality is inner factor influencing mooring rope. It is paid attention to ensure the stiffness,self-weight,minimum broken force to reach initial design requirement in wire rope design and production process. The corrosion speed of wire rope is decreased,the fatigue life of wire rope is increased by the following methods such as steel wire surface zinc plating,extrusion sheathing,good lubrication and block content,sacrificial anode and impressed current system.