自升式钻井平台就位时老脚印对桩靴性能的影响分析  

Effect of the footprint on the structure behavior of spud can during jackup emplacement

作　　者：赵军[1] 段梦兰[1] 宋林松[2] 李长亮[3] 张明辉 

机构地区：[1]中国石油大学(北京)海洋油气研究中心 [2]中海油田服务股份有限公司 [3]江汉石油钻头股份有限公司 [4]深圳赤湾胜宝旺工程有限公司

出　　处：《中国海上油气》2014年第5期104-108,115,共6页China Offshore Oil and Gas

基　　金：国家自然科学基金项目(编号:51379214)部分研究成果

摘　　要：由于受到老脚印影响,自升式钻井平台在老脚印附近位置就位时桩靴不可避免地要受到变化的偏心荷载作用,严重威胁着平台的就位作业安全。对自升式钻井平台在老脚印附近位置就位过程中桩基土体破坏机理受老脚印的影响进行了分析,在此基础上,根据桩靴不同阶段的受力特征将就位过程抽象为4个阶段,并以这4个阶段为4种不同的工况,对老脚印对桩靴结构性能的影响进行了分析。结果表明,自升式钻井平台就位过程中桩靴着力一侧桩腿、弦杆连接区杆件的应力较高;随着桩靴不断压入地层,桩靴底部承载面积增大,桩靴内部构件所受剪切应力显著减小:桩靴压桩至原有老脚印底部,受地层水平向强度分布不均的影响,较硬地层一端的组合应力并未因桩靴与桩基土体接触面积的增大而减小,相反由于端部硬地层的作用而大幅度增大,就位作业时应予重视。During the emplacement of jack-up rig nearby the existed footprint,the spud can would inevitably suffer varying eccentric loads by the subsoil due to the footprint,and consequently affect the security of the rig.The failure mechanism of the subsoil during spud can penetration nearby a footprint is investigated in this paper.On this basis,the process of such emplacement is divided into four stages according to the varied characteristics of the loads on the spud can.By taking the four stages as four different cases,the effects of footprint on the spud can structure capability is analyzed.It is shown from the analysis that 1） relatively higher stress occurred at the connected zone between leg and chords on the loaded side of spud can in the process of its emplacement; 2） the bearing area on the bottom of spud can increased with its further penetration,as a result,the shear stress within the internal structure of spud can decreased; 3） the combined stress presented different variation characteristics from the shear stress of spud can due to the uneven distribution of horizontal strength of the subsoil,in contrast to the decreasing shear strength,the combined stress at the side of spud can contacted with the stronger subsoil increased obviously when the spud can achieving the bottom of the original footprint,which should be highlighted in the future emplacement process.

关 键 词：自升式钻井平台 老脚印 桩靴 结构 破坏机理 

分 类 号：TE951[石油与天然气工程—石油机械设备]