一种适用于水下井口力学分析的新型砂土p-y模型  

A new sand p-y model for underwater wellhead mechanical analysis

作　　者：畅元江[1] 马海艇 王仕超 张玉[2] 张楠[1] 同武军 戴永国 CHANG Yuanjiang;MA Haiting;WANG Shichao;ZHANG Yu;ZHANG Nan;TONG Wujun;DAI Yongguo(Centre for Offshore Equipment and Safety Technology,China University of Petroleum(East China),Qingdao,Shandong 266580,China;College of Pipeline and Civil Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Deepwater Drilling&Production Technology Branch,CNOOC Ener Tech-Drilling&Production Co.,Zhanjiang,Guangdong 524067,China;Jiangsu Shuguang Petroleum Drilling Equipment Co.,Ltd.,Taizhou,Jiangsu 225532,China)

机构地区：[1]中国石油大学(华东)海洋油气装备与安全技术研究中心 [2]中国石油大学(华东)储运与建筑工程学院 [3]中海油能源发展股份有限公司工程技术深水钻采技术分公司 [4]江苏曙光石油钻采设备有限公司

出　　处：《天然气工业》2022年第11期88-97,共10页Natural Gas Industry

基　　金：国家自然科学基金面上项目“深水水下井口系统刚柔耦合动力学机理与损伤控制研究”(编号:52071337)。

摘　　要：深水海底浅层土壤是影响水下井口系统动态响应的重要因素,对井口系统的疲劳评估至关重要。目前水下井口动态分析时常采用API推荐的p-y模型模拟导管—土壤相互作用,但该模型没有考虑水下防喷器组(Blowout Preventors,简称BOPs)竖向重载对管土交互的影响,导致水下井口动态分析存在较大计算误差。为此,首先根据常规和新型p-y曲线的理论模型进行数值计算,然后采用ABAQUS软件建立实尺寸水下井口管土相互作用模型,加载计算得到BOPs重载下导管变形—土壤抗力仿真结果并与理论模型进行对比,最后采用缩尺土箱实验验证新型p-y模型在水下井口动态响应分析的正确性。研究结果表明:①采用新型p-y模型得到的导管弯矩、土抗力等数值计算结果与ABAQUS仿真和缩尺实验均吻合良好;②相对于常规管土模型,采用新p-y模型得到的水下井口弯矩、位移响应幅值等降低15%左右,得到的导管弯矩、位移响应幅值等降低幅度介于25%~30%;③新型砂土p-y模型充分考虑了BOPs竖向重载对管土相互作用的影响,在隔水管—水下井口系统力学分析中具有更好的适用性。结论认为,考虑到BOPs竖向重载对管土交互的影响,通过数值模拟及缩尺试验研究了新型p-y模型,并验证了其适应性,新模型有效提高了水下井口疲劳载荷计算的准确性,为水下井口系统疲劳评估提供了理论计算依据,为深海油气的开发提供了保障。Deep sea shallow soil is an important factor affecting the dynamic response of an underwater wellhead system and is crucial for the fatigue assessment of the wellhead system.In the current dynamic analysis of underwater wellhead,the p-y model recommended by API is often adopted to simulate the pipe-soil interaction,but it does not consider the influence of the vertical heavy load of underwater blowout preventers(BOPs)on the pipe-soil interaction,resulting in a considerable calculation error in the dynamic analysis of underwater wellhead.In this paper,numerical calculation is carried out by using the theoretical models of conventional and new p-y curves.Then,a pipe-soil interaction model of full-scale underwater wellhead is establish by using ABAQUS software,and the simulation results of conductor deformation–soil resistance under heavy load of BOPs are obtained and compared with the calculation results of theoretical model.Finally,the correctness of the new p-y model in analyzing the dynamic response of underwater wellhead is verified by performing a scaled soil box experiment.And the following research results are obtained.First,the numerical calculation results of conductor bending moment and soil resistance by the new p-y model are in agreement with the results of ABAQUS simulation and scaled experiments.Second,compared with the conventional pipe-soil model,the new p-y model is about 15%lower in the bending moment and deflection response amplitude of underwater wellhead and about 25%-30%lower in the bending moment and deflection response amplitude of conductor.Third,the new p-y model fully considers the influence of the vertical heavy load of BOPs on the pipe-soil interaction,so it is better applicable to the mechanical analysis of riser-underwater wellhead system.In conclusion,considering the influence of the vertical heavy load of BOPs on the pipe-soil interaction,a new p-y model is developed by means of numerical simulation and scaled experiment and its adaptability is verified.The new model effectively i

关 键 词：水下井口系统 新型p-y模型 管土相互作用 缩尺实验 动态响应 

分 类 号：TE52[石油与天然气工程—油气田开发工程]