基于区域分解法的潜孔锤无屈曲钻柱扭转振动研究

发布时间：2018-02-09 21:46

  本文关键词： 潜孔锤钻柱 区域分解法 粘滑振动 一维波动理论 固有模态　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：随着钻探工程的快速发展,越来越多的学者开始研究冲击回转钻进过程中的振动特性。潜孔锤以其特有的优点,得到越来越广泛的应用,对其进行系统的研究越来越迫切。本文以潜孔锤钻柱为例,基于区域分解法来建立钻柱离散动力学方程,研究钻柱含有扭转粘滑的振动规律,具体研究内容如下:一、建立了潜孔锤钻柱变截面模型,通过区域分解法,应用广义变分原理对潜孔锤钻柱建立能量泛函,通过泛函变分求解驻值的方法来得到钻柱的动力学离散方程,并应用matlab软件编程,完成了钻柱耦合振动响应的系统求解过程,并应用Newton-Raphson法求解钻柱非线性载荷问题,根据钻柱振动状态自适应调整载荷,从而建立包含钻柱非线性问题的钻柱耦合振动响应求解系统。二、利用建立的钻柱耦合振动求解系统,研究了钻柱阻尼和变截面等因素对钻柱耦合振动响应的影响。在此基础上,研究针对潜孔锤冲击周期冲击激励钻柱扭转粘滑振动特性,分析了冲击持续时间、钻柱长度和驱动转速对扭转粘滑运动的影响。结果显示:冲击时间越长,越容易发生粘滑振动现象;与短钻柱相比,长钻柱扭转振动各阶模态频率间距减小,钻柱在每一冲击倍频处均接近的模态频率,易发生扭转共振;钻柱的驱动速度提高时,钻头扭转动能增大,钻头阻力矩可能无法完全消耗钻头动能,使不再发生粘滑振动现象。三、通过一维波动理论,建立了弹性体钻柱扭转振动的数学理论模型,应用振型叠加法得到周期力作用下钻柱扭转稳态受迫振动响应,得到了线性条件下钻柱扭转振动的理论求解方法,与区域分解法结果进行对比,验证了两种方法的可靠性。从中可以看出,区域分解法所得的响应是由钻柱的瞬态响应和稳态响应叠加而成,而理论法所得的响应中只有稳态响应。区域分解法与理论法可以很好地求解短钻柱扭转振动响应,而由于长钻柱以高阶振动为主,区域分解法在模拟长钻柱振动更有优势。通过对潜孔锤钻柱耦合振动规律的研究以及非线性动力学求解的探讨,更全面地了解了潜孔锤钻柱振动特性,对实际钻进起到重要的指导意义,本文为钻柱振动响应的研究提供了重要的方法和理论基础。
[Abstract]:With the rapid development of drilling engineering, more and more scholars begin to study the vibration characteristics of percussive rotary drilling. It is more and more urgent to study it systematically. In this paper, the discrete dynamic equation of drill string is established based on region decomposition method, and the vibration law of drill string with torsional stick-slip is studied. The main contents are as follows: 1. The variable cross section model of DTH hammer drill column is established. By using the domain decomposition method, the energy functional of DTH hammer drill string is established by applying the generalized variational principle, and the dynamic discrete equation of drill string is obtained by using functional variational method to solve the standing value of drill string. The system solution of the coupling vibration response of drill string is completed by using matlab software, and the nonlinear load problem of drill string is solved by Newton-Raphson method. The load is adjusted adaptively according to the vibration state of drill string. Thus, the system for solving the coupled vibration response of drill string including the nonlinear problem of drill string is established. Second, the system is established to solve the coupled vibration of drill string. The effects of damping and variable cross section of drill string on the coupled vibration response of drill string are studied. On the basis of this, the torsional viscous slip vibration characteristics of drill string induced by impact cycle of DTH hammer are studied, and the impact duration is analyzed. The effect of drill string length and driving speed on torsional sticking-slip motion. The results show that the longer the impact time, the more likely is the phenomenon of stick-slip vibration, and compared with the short drill string, the distance between the frequencies of the torsional vibration of the long drill string decreases. It is easy to produce torsional resonance when the drill string is close to the frequency of every impact frequency. When the driving speed of drill string increases, the bit torsional kinetic energy increases, and the bit resistance moment may not completely consume the bit kinetic energy. Third, through one-dimensional wave theory, the mathematical model of torsional vibration of elastic drill string is established, and the response of steady state forced vibration of drill string under periodic force is obtained by using mode superposition method. The theoretical solution of torsional vibration of drill string under linear conditions is obtained. The results of the method are compared with the results of the domain decomposition method, and the reliability of the two methods is verified. The response obtained by the domain decomposition method is superposed by the transient response and the steady response of the drill string, while the response obtained by the theoretical method is only the steady-state response. The region decomposition method and the theoretical method can solve the torsional vibration response of the short drill string well. Because the long drill string is dominated by high order vibration, the region decomposition method is more advantageous in simulating the long drill string vibration. Through the study of the coupling vibration law of the down-hole hammer drill string and the discussion of the nonlinear dynamic solution, The vibration characteristics of DTH hammer drill string are fully understood, which plays an important guiding role in actual drilling. This paper provides an important method and theoretical basis for the research of drill string vibration response.
【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】：P634.3
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本文编号：1498930