RTTS封隔器外中心管疲劳寿命分析  

Fatigue Life Analysis on the Outer Center Tube of RTTS Packer

作　　者：王智勇 朱帅 曹银萍[2] 万志国 窦益华[2] Wang Zhiyong;Zhu Shuai;Cao Yinping;Wan Zhiguo;Dou Yihua(School of Railway Equipment Manufacturing,Shaanxi Railway Institute;Mechanical Engineering College,Xi'an Shiyou University)

机构地区：[1]陕西铁路工程职业技术学院铁道装备制造学院,陕西省渭南市714000 [2]西安石油大学机械工程学院

出　　处：《石油机械》2024年第6期96-102,共7页China Petroleum Machinery

基　　金：陕西省教育厅2022年度一般专项科研计划项目“基于连续介质力学离散元方法的封隔器力学性能研究”(22JK0331);陕西铁路工程职业技术学院科学研究基金项目“橡胶密封件非线性有限元仿真及性能评价”(KY2021-24);横向课题“封隔器系统非线性仿真及安全性评价”(STYKJ2021-055)。

摘　　要：RTTS封隔器是封隔高温高压井油套环空压力的关键工具,其外中心管的失效会导致油套环空窜通,引发严重事故。为完善外中心管的失效评估体系,基于静强度、疲劳强度理论,采用有限元仿真方法溯源外中心管失效原因;建立外中心管全尺寸三维模型,简化出有限元模型,拟合外中心管材料42CrMo的材料本构模型和S-N寿命曲线;考虑坐封、射孔2种典型工况极限载荷作用下外中心管的静强度分析,将分析结果传递到NCode疲劳仿真平台,依据疲劳强度理论,进行不同平均应力载荷、不同循环特性载荷作用下的外中心管疲劳强度分析。研究结果表明:在150 kN轴向坐封载荷作用下外中心管发生高周疲劳破坏,在300 kN轴向射孔载荷作用下外中心管发生低周疲劳破坏;不同循环特性载荷对中心管寿命影响差异较大,对称循环载荷对外中心管疲劳寿命缩短最为明显。所得结论可为外中心管甚至封隔器的性能评估、优化提供技术支撑。The RTTS packer is a key tool for sealing the tubing-casing annulus pressure of high-temperature and high-pressure wells,and the failure of its outer center tube can lead to channeling of tubing-casing annulus,thus causing serious accidents.In order to improve the failure evaluation system of the outer center tube,based on the theory of static strength and fatigue strength,the finite element simulation method was used to trace the cause of failure of the outer center tube;then,a full-scale 3D model of the outer center tube was built,and the finite element model was simplified to fit the material constitutive model and S-N life curve of the outer center tube material 42CrMo;third,the static strength of outer center tube under ultimate loading under 2 typical working conditions such as setting and perforation was analyzed;finally,the analysis results were transmitted to the NCode fatigue simulation platform,and the fatigue strength of outer center tube under different average stress loads and different cyclic characteristic loads was analyzed based on fatigue strength theory.The research results show that under an axial seating load of 150 kN,the outer center tube undergoes high cycle fatigue failure;under an axial perforation load of 300 kN,the outer center tube undergoes low cycle fatigue failure;different cyclic characteristic loads have largely different impact on the service life of the outer center tube,and symmetric cyclic loads have the most significant reduction in the fatigue life of the outer center tube.The conclusions provide technical support for the performance evaluation and optimization of the outer center tube or even the packer.

关 键 词：RTTS封隔器 外中心管 疲劳寿命 循环特性 

分 类 号：TE921[石油与天然气工程—石油机械设备]