自升式平台方形桩靴“踩脚印”时结构强度计算方法  

Calculation Method of Structural Strength for Square Spudcan Installation near the Footprints

作　　者：高杰[1] 刘军鹏[1] 黎建波 李明婕 段梦兰[1] GAO Jie;LIU Jun-peng;LI Jian-bo;LI Ming-jie;DUAN Meng-lan(College of Safety and Ocean Engineering,China University of Petroleum(Beijing),Beijing 102249,China;China Oilfield Services Limited Co.,Ltd.,Sanhe 065201,China;College of Energy and Mechanical Engineering,Dezhou University,Dezhou 253023,China)

机构地区：[1]中国石油大学(北京)安全与海洋工程学院,北京102249 [2]中海油田服务股份有限公司,三河065201 [3]德州学院能源与机械学院,德州253023

出　　处：《科学技术与工程》2022年第32期14198-14205,共8页Science Technology and Engineering

基　　金：国家自然科学基金(51909030);中海油田服务股份有限公司资助项目(ZJB16YF007)。

摘　　要：桩靴是自升式平台的基础,对整个自升式平台起到支撑和稳定的作用。在自升式钻井平台“踩脚印”的过程中,桩靴底部受到土体不均匀的承载力,可能会造成桩靴局部应力过大,进而导致桩靴损坏。鉴于自升式钻井平台“踩脚印”对桩靴结构的潜在危险,设计了三桩腿的自升式钻井平台“踩脚印”试验模型,获得了不同入泥深度时桩靴底部的压力分布状况。通过分析发现,在入泥深度为5 m时,桩靴两端产生最大的压力差,而在入泥深度为15 m时,桩靴底部压力最大,根据不同入泥深度对应的桩靴底部压力分布值构造了二次多项式函数,在此基础上,采用有限元软件ABAQUS建立了详细的方形桩靴有限元模型,将构造的压力分布函数按照分布规律分别施加到桩靴底部,计算出桩靴在不同深度以及不同偏心距时的桩靴应力结果。结果表明:在“踩脚印”过程中,应力最大位置出现在桩靴顶部圆管以及底部壳板位置,桩靴底部两侧受力不平衡对桩靴强度计算具有较大影响,相比直接将最大压载施加到桩靴底部的保守计算方式,本文方法和计算结果更加接近实际工程工况。Spudcan is the foundation of jack up platform,which plays a role in supporting and stabilizing the whole jack up platform.In the process of“stepping on the footprints”of jack up drilling platform,the bottom of spudcan is subjected to uneven bearing capacity of soil,which may cause excessive local stress of spudcan and lead to damage of spudcan.In view of the potential danger of the“footprints”of the jack up drilling platform to the spudcan structure,the“footprints”test model of the jack up drilling platform with three legged was designed,and the pressure distribution at the bottom of the spudcan at different mud entry depths was obtained.Through analysis,it is found that when the mud entry depth is 5 m,the maximum pressure difference occurs at both ends of the spudcan,while when the mud entry depth is 15 m,the pressure at the bottom of the spudcan is the largest.A quadratic polynomial function was constructed according to the pressure distribution value at the bottom of the spudcan corresponding to different mud entry depths.On this basis,a detailed finite element model of the square spudcan was established by using the finite element software ABAQUS,and the constructed pressure distribution function was applied to the bottom of the spudcan according to the distribution law,The stress results of spudcan at different depths and eccentricities were calculated.The results show that in the process of“stepping on the footprints”,the maximum stress occurs in the circular pipe at the top of the spudcan and the shell plate at the bottom.The force imbalance on both sides of the bottom of the spudcan has a great impact on the strength calculation of the spudcan.Compared with the conservative calculation method of directly applying the maximum ballast to the bottom of the spudcan,the proposed method and calculation results are closer to the actual engineering conditions.

关 键 词：自升式钻井平台 方形桩靴 “踩脚印” 偏心距 

分 类 号：TE951[石油与天然气工程—石油机械设备]