【作者】 高敦升；

【导师】 沈跃；

【作者基本信息】 中国石油大学 ， 物理学， 2010， 硕士

【摘要】 随钻测量(MWD)技术是一种在钻井过程中进行井下信息实时测量和上传的现代钻井辅助技术。随钻测量通常是通过钻井液信息遥测系统进行井下数据的传输,其中钻井液压力波发生器是钻井液信息遥测系统的核心设备。为提高信息传输速率,目前先进的钻井液信息遥测系统采用基于旋转阀或振荡剪切阀的连续压力波发生器及频带方式进行井下数据的传输。本文通过对钻井液压力波的产生机理、旋转阀阀口的结构设计及旋转阀转子受力情况等进行理论研究,为钻井液连续压力波发生器的研制提供理论指导。根据流体力学非稳定流的水击理论研究了钻井液压力波的产生机理,构建出钻井液压力波数学模型,并结合旋转阀的特点构建出正弦压力波数学模型,研究了阀孔开度与压力幅度的理论关系。根据对四阀孔旋转阀产生水击压力的过程分析及结构特点,通过建立面积微元分别对旋转阀定、转子阀孔的结构进行了数学建模与计算,在不考虑转子机械运动特性的理想情况下,确定出产生正弦压力信号的定、转子阀孔结构与几何参数,为旋转阀转子在最小受力状况下产生正弦压力的阀孔参数设计提供了理论依据。根据工程流体力学的相关理论及钻井液压力波数学模型,对旋转阀转子进行了轴向受力分析,分析了在水击压力及阀孔节流阻力作用下转子受到的旋转阻力矩。数值计算表明,转子受到的轴向力主要由阀孔节流阻力产生,且随阀孔的开度呈非线性变化,当阀孔接近全关闭时,该力作用于转子止推轴承上会产生相当大的负荷及转子旋转阻力矩。通过转子的轴向受力分析,可以为止推轴承的参数确定及变阻力矩情况下转子的驱动控制方法提供理论依据。更多还原

【Abstract】 Measure while drilling (MWD) is a kind of modern drilling supporting technology, which can real-time measure and transmit the downhole information during the drilling process. MWD usually transmits the downhole data by the drilling fluid information telemetry system, in which drilling fluid pressure wave generator is the core device. To improve the information transmission rate, the current advanced drilling fluid information telemetry system transmits the downhole data by the continuous pressure wave generator, which is based on rotary valve or oscillating shear valve, and transmits downhole data in a bandwide mode. This paper conducts the theoretical investigation on the generation mechanism of drilling fluid pressure wave, the design of the rotary valve and the force condition of the rotary valve rotor, etc, aims to provide theoretical guidance for the development of the continuous pressure wave generator.According to the non-steady flow water hammer theory of hydromechanics, a mathematical model of drilling fluid pressure wave is built by study of the pressure wave generating mechanism. Combining the characteristics of rotary valve, the mathematical model of sinusoidal pressure wave is built, and the theoretical relationship between the valve hole opening extent and the pressure amplitude is studied. According to the process analysis and the structural characteristics of a four-valve holes rotary valve producing the water hammer pressure, the structure and geometric parameter of the rotary valve stator and valve hole of rotor are determined by mathematical modeling and calculation respectively based on the establishment of surface micro-element in the condition of not considering the mechanical motion characteristics of the rotor. Those can provide a theoretical basis for the valve hole parameters design for the rotary valve rotor generates the sinusoidal pressure under the minimum force condition.According to related theories of engineering hydromechanics and mathematical model of drilling fluid pressure wave, combining with the axial force analysis on rotary valve rotor, the rotary resistive torque of rotor under the effect of water hammer pressure and the throttle resistance of valve hole is analyzed. Numerical calculations show that the axial force on the rotor is mainly generated by the throttle resistance of valve hole, and it linearly changes with the valve hole opening. When the valve hole almost all shuts down, this force will have a considerable load and rotor rotary resistive torque on the rotor thrust bearing. Through the axial force analysis of the rotor, it will provide theoretical basis for the determination of the thrust bearing parameters and the drive and control method of the rotor in the case of variable resistive torque.更多还原