超深井钻柱动态疲劳失效特征及参数优选  

Dynamic Fatigue Failure Characteristics and Parameter Optimization of Drill Strings in Ultra-Deep Wells

作　　者：王文昌[1,2] 徐祖凯 周星[1,2] 王昭彬 陈锋 WANG Wenchang;XU Zukai;ZHOU Xing;WANG Zhaobin;CHEN Feng(School of Mechanics and Engineering Sciences,Shanghai University,Shanghai,200072,China;Shanghai Institute of Applied Mathematics and Mechanics,Shanghai,200072,China;School of Mechatronic Engineering and Automation,Shanghai University,Shanghai,200444,China)

机构地区：[1]上海大学力学与工程科学学院,上海200072 [2]上海市应用数学和力学研究所,上海200072 [3]上海大学机电工程与自动化学院,上海200444

出　　处：《石油钻探技术》2024年第2期118-125,共8页Petroleum Drilling Techniques

基　　金：国家自然科学基金面上项目“考虑隔水管耦合作用的超深水超深曲井钻柱动力学研究”(编号:52174003);国家自然科学基金石油化工联合基金重点项目“超深井钻柱非线性动力学及动态安全性基础理论研究”(编号:U1663205);国家自然科学基金面上项目“特深井“钛-钢”复合钻柱动态安全性及异型材质接头失效机理研究”(编号:52374008)联合资助。

摘　　要：随着油气勘探深度不断增大,超深井钻柱井下振动更加复杂,应力状态随时间变化显著,为保障超深井钻柱的安全性,开展了受空间挠曲井筒约束超细长钻柱的动态疲劳失效特征研究,并进行钻柱结构及工作参数优选。基于实际井眼轨迹,考虑钻柱与井壁的碰撞特征,通过有限元仿真分析,得到全井钻柱动力学特性;根据疲劳损伤累积理论,研究了超深井全井钻柱在非对称循环变幅应力状态下的疲劳强度;结合现场实例,研究了超深井钻柱的危险截面,分析了钻柱疲劳强度随转速、钻压和稳定器安装位置的变化规律。研究表明:钻压和高转速对钻柱疲劳强度的影响较大,低转速对钻柱疲劳强度的影响较小;稳定器可以大幅降低底部钻具组合疲劳失效的概率,而且稳定器安装位置对钻柱疲劳强度的影响较为显著。研究结果为超深井钻柱组合结构参数和钻井参数优选提供了理论依据。With the increasing depth in oil and gas drilling,the downhole vibration of drill strings in ultra-deep wells is very complex and the stress state changes significantly with time.In order to ensure the safety of drill strings in ultra-deep wells,the dynamic fatigue failure characteristics of ultra-thin and ultra-long drill strings constrained by spatially deflected wellbores were studied,and the structure and working parameters of drill strings were optimized.Based on the actual wellbore trajectory,the collision characteristics of the drill string with the borehole wall were considered,and the dynamic characteristics of the drill string were obtained through finite element simulation analysis.The fatigue strength of the drill string in ultra-deep wells under the variable asymmetric cyclic stress state was studied according to the accumulated fatigue damage theory.According to actual field case,the dangerous cross-section of the drill string in ultra-deep wells was analyzed,and the variation law of fatigue strength of the drill string with rotation speed,weight on bit(WOB),and stabilizer position was studied.The research demonstrated that WOB and high rotation speed have a great effect on the fatigue strength of the drill string,and low rotation speed slightly affects the fatigue strength of the drill string.After the stabilizer is installed,the probability of fatigue failure of the bottom hole assembly(BHA)can be greatly reduced,and the stabilizer position has a significant effect on the fatigue strength of the drill string.The research results provide a theoretical basis for the optimization of the structure and drilling parameters of drill strings in ultra-deep wells.

关 键 词：超深井 钻柱 动态应力 碰撞接触 疲劳强度 参数优选 

分 类 号：TE21[石油与天然气工程—油气井工程]