声波钻钻柱疲劳损伤及其惯性边界的耦合特征研究

发布时间：2018-08-04 18:44

【摘要】：随着钻探技术的发展以及对环境保护的日益重视,对于钻探设备、工具的要求也越来越高,声波钻进技术因具有钻进速度快、适应地层广和环境污染少等优点,近年来得到了迅速的发展和广泛的应用。本文针对振动器质量(不包括通过隔振器连接的回转器部分)对惯性边界声波钻柱动力学特性和振动响应的影响,以及声波钻钻柱疲劳损伤的问题,开展了理论研究工作,具体研究内容如下:一、建立了惯性边界声波钻柱动力学微分方程,采用数学分析方法求解惯性边界声波钻柱的固有频率方程得到其近似解通式,并分析讨论了振动器质量、钻柱长度、钻柱密度和截面积等系统参数对钻柱的固有频率的影响。二、采用分离变量法求解惯性边界声波钻柱动力学微分方程,得到惯性边界声波钻柱的稳态位移、应力响应;分析了振动器质量对惯性边界声波钻柱位移、应力响应,以及钻头位移幅值、钻柱顶端振动器与钻柱耦合处应力幅值的影响。三、声波钻利用钻柱高频共振实现快速钻进时,钻柱内的高频交变应力容易引起钻柱疲劳损伤,通过对声波钻行波与驻波振动阶段钻柱内应力分析,基于疲劳累积损伤法则,建立了钻柱疲劳损伤计算公式;声波钻柱内的疲劳损伤区段在靠近钻头处不超过驻波起振长度的范围内。通过以上研究,有利于精确控制声波钻机浅孔钻进时钻柱的振动频率,提高钻进效率与声波钻进机具及钻杆的使用寿命,指导声波钻机设计和声波钻进生产实践;同时声波钻钻柱疲劳损伤计算方法也为受对称循环应力作用的钻柱疲劳寿命估算提供了理论参考。
[Abstract]:With the development of drilling technology and the increasing attention to environmental protection, the requirements for drilling equipment and tools are becoming higher and higher. Acoustic drilling technology has the advantages of fast drilling speed, wide adaptability to formation and less environmental pollution. In recent years, it has been rapidly developed and widely used. In this paper, the influence of vibrator mass (not including the rotary part connected by the isolator) on the dynamic characteristics and vibration response of the inertial boundary acoustic drill string and the fatigue damage of the acoustic drill string are studied theoretically. The specific research contents are as follows: first, the dynamic differential equation of inertial boundary acoustic drill string is established, and the approximate general solution of the natural frequency equation of inertial boundary acoustic drill string is obtained by using mathematical analysis method, and the vibrator mass is analyzed and discussed. The influence of system parameters such as drill string length, drill string density and cross section area on the natural frequency of drill string. Secondly, the dynamic differential equation of inertial boundary acoustic drill string is solved by the method of separating variables, the steady displacement and stress response of inertial boundary acoustic drill string are obtained, and the response of vibrator mass to displacement and stress of inertial boundary acoustic drill string is analyzed. The effects of drill displacement amplitude and stress amplitude at the coupling of drill string top vibrator and drill string are also discussed. Third, when the high frequency resonance of drill string is used to realize the rapid drilling, the high frequency alternating stress in the drill string can easily cause fatigue damage of the drill string. By analyzing the internal stress of the drill string in the vibration stage of the acoustic drilling wave and standing wave, the fatigue cumulative damage rule is based on. The formula for calculating fatigue damage of drill string is established, and the fatigue damage section of sonic drill string is within the range of standing wave vibration initiation length near the drill bit. Through the above research, it is advantageous to accurately control the vibration frequency of drill string during shallow hole drilling of sonic drilling rig, to improve drilling efficiency and the service life of acoustic drilling machine and drill pipe, and to guide the design of sonic drilling rig and the production practice of sonic drilling. At the same time, the fatigue damage calculation method of sonic drill string also provides a theoretical reference for the fatigue life estimation of drill string subjected to symmetrical cyclic stress.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P634

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