封隔器系统工作行为仿真研究

【作者】 湛精华；

【导师】 刘清友；

【作者基本信息】 西南石油大学 ， 机械设计及理论， 2005， 博士

【摘要】 本文从系统的角度出发，综合应用弹塑性力学、接触有限元理论、数值分析方法、计算机仿真技术等多学科知识，在国内率先建立了考虑胶筒非线性、大变形特征的封隔器系统工作行为仿真模型，并通过实验建立了封隔器胶筒材料在井底实际工况下的本构关系模型。为了将所建立的仿真模型更好地应用到封隔器的设计上，本文运用混合编程思想开发了具有自主知识产权的封隔器系统工作行为仿真软件，并在自行设计的封隔器试验台架上完成了Y341-148型封隔器台架试验，验证了所建立数学模型和所开发仿真软件的正确性，为封隔器及井下工具的设计、改进和新产品开发提供了一种新的理论方法和技术手段，进一步提高了我国封隔器的设计理论和研究水平。论文的研究工作及创新点主要体现在以下几个方面： (1) 建立了Y341-148型封隔器零部件的三维实体模型，进行了结构装配和运动干涉检验，运用有限元分析软件对其关键零部件进行了有限元分析和结构优化，根据分析结果对现有封隔器的结构提出了改进意见，增强了现有Y341-148型封隔器的可靠性，提高了其工作性能； (2) 胶筒是封隔器的关键部件，由于目前国内尚缺乏封隔器胶筒在井底实际工况下的材料力学性能参数，本文采用中国燃气涡轮研究院的SB802热-机综合疲劳试验机开展了封隔器胶筒目前所用4种橡胶材料在模拟实际工作环境下的力学性能试验研究，测定了这4种橡胶材料在不同载荷、不同温度下的应力-应变数据，建立了与井下实际工况相对应的胶筒材料本构关系，为建立封隔器胶筒接触有限元模型、封隔器系统工作行为仿真模型提供了数据基础，为仿真软件的运行提供了可靠的参数； (3) 根据封隔器胶筒在工作过程中的非线性、大变形特征，将胶筒柔性体与胶筒座、套管壁等刚性体运动过程中的接触区域处理为持续变化的非线性边界条件，建立了封隔器胶筒的非线性接触有限元模型。模型中采用变节点的四边形等参单元，依据结构特征、应力集中程度确定了网格大小密度和分布方式，预设了结构尺寸参数以便于结构尺寸变化后网格自动离散。该模型的建立为开展封隔器系统在井底真实工况下的工作行为仿真研究奠定了基础： (4) 综合运用弹塑性力学及有限元分析的理论和方法，根据封隔器的工作状态和其零部件在工作过程中的运动、受力、变形特征及其相互作用关系，将封隔器简化为轴对称形式，率先在国内建立了考虑胶筒大变形特征的封隔器系统工作行为仿真模型，该模型可以模拟封隔器在坐封、密封、解封三种工况下的运动过程和力学行为，真实的反应封隔器在工作过程中包括胶简在内各零部件的运动、受力和变形情况，为封隔器的设计和新产品的开发提供了新的理论依据； (5) 针对仿真模型中胶筒柔性体的非线性、大变形特征和金属零件的线性、小变更多还原

【Abstract】 In this paper, from a system point, through setting up packer system linear and non-linear contact finite element analyzing models the packer system’s working action simulating research are developed by the way of compute simulating technic combined with production fact, which provide the new theory reference and method for analyzing the packer’s down-hole working performance and designing new type of packer. The paper’s main contents come from the science research named the Structure Optimizing and Working Action Simulating Research of Down-hole Packer that are developed by South West Petroleum Institute and JiangHan Oil Withdrawal Technology Research Institute that is a subcompany of China Petrochemical Corporation in JiangHan oil field. The detail research works are as follows:1. The mechanics performance experiment to the four rubber materials of packer that are provided by JiangHan Oil Withdrawal Technology Research Institute have been completed using Fuel Gas Turbine Academy of China’s SB802 heat& machine compositive fatigue tester. The mechanics performance of four rubber materials under different load and temperature condition have been determined and the rubber materials’ constitutive relation models have been gained, which provide the requisite material parameter for establishing the packer system’s finite element simulating models;2. For setting up scientific and rational finite element models, the rational simplification to the packer system is completed and the twenty-two parts’ discretization are realized according to the finite element analyzing demand. Determining the finite element’s shape, number and division project, setting up the all parts’ structure, elements and node division project data-base and realizing the mesh’s automatic division using the finite element program developed; Using the theory of contact linear and non-linear finite element, establishing the packer system’s seating, sealing and release sealing working process finite element models and working action simulating models combined the packer’s working mechanism and structure feature. Researching the packer system’s frictional contact problem by the way of virtual contact loads and simulating the packer’s working process correctly; To the non-linear large deformation problem of sealing rubber, it’s large deformation feature and law of motion embody the packer’s seating and sealing working process. In the paper, establishing the rubber’s finite element models and simulating models by the way of geometrical and material non-linear contact problem and realizing the models’ solve. Finding out the packer rubber’s law of distortion and stress changing status更多还原