海流涡激效应对钻井隔水导管疲劳强度的影响

钻井隔水导管是从海上钻井平台下到海底浅层的套管,在海上钻完井过程中起着非常重要的作用。在深水海域,由于隔水导管泥线以上长度的增加,海流对钻井隔水导管疲劳强度影响作用加剧,从而影响隔水导管的使用寿命。开展海流涡激效应对钻井隔水导管疲劳强度影响研究,能够为钻井隔水导管尺寸和材料选择提供科学依据。文中对隔水导管进行了力学分析,将隔水导管受力模型简化为下部固定,上部简支的梁模型来分析。利用流体阻尼及流体涡激力理论模型,计算海流作用下涡激效应对于隔水导管疲劳强度的影响。结合南海某海域的海况资料,对海上钻井隔水导管的疲劳强度和使用寿命进行了分析和校核,给出了该海域合理的隔水导管尺寸。通过研究得出:随着水深的增加,海流对隔水导管的涡激效应会逐渐加强,对隔水导管疲劳强度影响加剧。

Current vortext - induced effect to drilling riser fatigue strength

Drilling riser is the casing from offshore drilling plateform to subbottom,it plays an important role in offshore completion.In deep sea,with the increasing of riser length above mudline,the current vortext-induced effect to drilling riser fatigue strength is adding,so the riser life is decreased.The research could offer science basis to riser size and material choosing.In this paper,the mechanical analyses of the riser had been made,it simplifies the mechanical model as the low fixed and the top simply supported beam.Based on liquid damping and vortex-induced force theoretic model,calculated it's fatigue strength.Interacted with oceanic condition of an area from South China Sea,fatigue strength and service life of offshore drilling riser were analysed and checked,eventually,the reasonable size was provided.From the research:with the depth increasing,current vortext-induced effect will gradually strengthen,and the influence to fatigue strength aggravates.