浅海重力式海洋平台稳定性数值模拟与离心机试验研究

Numerical simulation and centrifuge test study on stability of gravity offshore platform in shallow sea

重力式海洋平台是集钻、采、贮、运等设施于一体的采油平台,广泛应用于近海边际油田中。在多重海洋荷载作用下,海洋平台处于复杂应力状态中,为满足结构安全运行的要求,需要分析确定平台结构和地基受力变形。依托旅大29-1边际油田开发项目,结合“863”项目“浅海重力式平台水下储油技术”所建议的平台设计方案,开展了数值模拟计算和离心模型试验,明确了浅海重力式平台结构变形规律、地基土体位移规律和破坏模式。研究表明:在环境荷载作用下平台整体结构产生较明显的侧向变形,甲板结构产生翘曲变形,地基表层土体竖向沉降量较大;平台没有设置裙板时,平台与地基之间以发生滑移变形为主,平台增加5 m长裙板时,平台与地基之间以绕底板的转动变形为主,同时上部平台结构均发生了倾斜。此结果可为重力式海洋平台的建造和结构优化提拱技术参考依据。

Gravity offshore platform,as an oil production platform that integrates drilling,production,storage and transportation facilities,has been widely used in offshore marginal oil field.Under the multiple marine loads,offshore platform is in the complex stress state.In order to meet the structural safety operation requirements,it is necessary to analyze the stress deformation of platform structure and foundation.Based on the LD 29-1 marginal oil field development project,combined with the platform design scheme suggested in"Shallow sea gravity platform underwater oil storage technology",numerical simulation calculations and centrifuge model tests were carried out.The deformation law,foundation soil displacement law,and failure mode of shallow sea gravity platform structure were determined.Results show that the overall structure of the platform has obvious lateral deformation under the action of marine load,the deck structure warped and the vertical settlement of surface foundation is large.When there is no bucket skirt on the platform,sliding deformation mainly occurs between the platform and the foundation,and when a 5 m long bucket skirt is added to the platform,the rotational deformation around the bottom plate mainly occurs between the platform and the foundation,while the upper platform structure has inclined.The results can provide technical reference for the construction and structural optimization of gravity offshore platforms.