【作者】 侯勇俊；

【导师】 张明洪；

【作者基本信息】 西南石油学院 ， 机械设计及理论， 2002， 博士

【摘要】 本文研究了一种采用新型筒式结构筛网的钻井振动筛，其筛网是将普通平板筛网或波纹锥形筛网卷制成筒形结构，并可安装在现有的钻井振动筛上。工作时筛网筒与筛箱一起振动，同时还绕自身轴线作缓慢的旋转运动，从环空返回的钻井液进入筛筒内部进行分离。其主要特点是：自洁作用很强，没有“筛糊”、“筛堵”现象；采用大抛掷指数提高振动筛处理能力时可避免钻井液的剧烈飞溅现象；可实现在封闭的空间里进行钻井液的筛分，因而在欠平衡钻井等新钻井技术的应用中也可发挥其用武之地。但这种新型振动筛提出的时间不长，迄今为止，还未有人从理论和试验上对其进行过研究。为了弄清这种振动筛的工作机理，为开发新产品提供理论指导，因此本文针对这种振动筛作了一些开拓性的工作，并完成了以下几个方面的研究。 (1)根据机械系统动力学建立了双轴自同步平动椭圆振动筛和三轴自同步平动椭圆振动筛的动力学方程。从振动筛偏心轴的振动力矩方程出发，导出了双轴自同步平动椭圆振动筛的自同步条件和稳定运转条件。利用分析动力学理论导出了三轴自同步平动椭圆振动筛的自同步条件和稳定运转条件。在此基础上，提出了双轴和三轴自同步平动椭圆振动筛的力心理论，为开发新型钻井振动筛提供了理论依据。 (2)从筒式筛网上单颗干固相颗粒的受力分析着手，讨论了颗粒在筒式筛网面上的切向相对滑动和轴向相对滑动及滑动条件，并导出了颗粒从进料端向出料端滑动运移平均速度；讨论了颗粒的抛掷运移，给出了筒式筛网上的抛掷指数及其变化规律，提出了筒式筛网的平均抛掷指数的概念及计算方法，研究了筒式筛网上颗粒抛掷运移的产生条件和终止条件，以及颗粒抛掷运移的输送速度；还讨论了筒式筛网的旋转角速度对颗粒抛掷运动产生的影响。 (3)根据钻井液在筒式筛网上的流动特点，建立了筒式筛网上钻井液沿轴线方向流动、周向流动和透筛流动的流动方程，以及钻井液的连续流动方程，利用特征线法写出了筒式网上钻井液流动模型的特征差分方程，并作了理论分析。 (4)建立了筒式筛网上非淹没状态下湿固相单颗粒的滑动运移和抛掷运移模型，给出了滑动运移和抛掷运移的速度计算方法。同时从非淹没区固相颗粒群的实际运移表现出的连续流动现象出发，运用拟流体假设，建立了非淹没区湿固相颗粒群的运移模型。分别对干颗粒模型、湿颗粒模型和颗粒群模型分别进行了理论计算，并与实验数据作了对比分析。 O）从颗粒在钻井液中的受力情况出发，分析了颗粒在淹没状态下的抛掷指数和起抛条件，以及起抛以后在钻井液中的运移规律。 的）给出了筒式筛网钻井振动筛对纯钻井液处理能力的计算公式。依据串联介质的渗流理论，同时考虑固相颗粒与筛网间的干涉，建立了筒式筛网对含屑钻井液实际处理能力的计算方法。 理论分析和实验结果均表明，本文对筒式网振动筛的工作理论的研究是可行的，其中部分研究成果已经成功应用于生产实践。更多还原

【Abstract】 This paper is about studies of a new type of shale shaker using a new roller-structure screen, which is made by winding the normal flat screen or corrugated pyramid screen into rotter screen, and can be installed on the shale shakers being used in the oil fieM. When the shaker is working, its roller screen not only vibrates with the shaker deck, but also slowly rotates with the axis of itself, and the drilling fluids returned from annular space are separated inside the roller screen. This kind of shaker has such features: its self-cleaning effect is powerful, no phenomena of screen pasting and screen jam happen, when improving the treating capacity by increasing throwing coefficient, the phenomena of drilling fluids spattering can be avoided, so that screening-separating drilling fluids in closed space can be realized. Hence, this new kind of shale shaker will find its application in the new drilling techniques such as under-balanced drilling. It is not a long time that the idea of this kind of shale shaker is presented, no one has done the theoretic studies and test studies on this kind of shale shaker so far. In order to clarify the working theory of a roller screen shale shaker and provide for developing this new product, the paper does some this roller screen shale shaker and has completed following studies.(1) On the basis of machinery system dynamics, the dynamics equations of balanced elliptical shakers excited by two-shaft self-synchronizing and by three-shaft self-synchronizing are established. From vibrating torque equations of shaker’s exciting shafts, the self-synchronizing condition and synchronizing state stability condition of balanced elliptical shakers excited by two-shaft self-synchronizing are obtained. According to analysis dynamics theory, the self-synchronizing condition and synchronous state stability condition of balanced elliptical shakers excited by three-shaft self-synchronizing are inferred. Then the force center theories of balanced elliptical shakers excited by two-shaft self-synchronizing and by three-shaft self-synchronizing are established, which can provide theoretical foundations for designing new kinds of shale shakers.(2) Starting off with analyzing the forces affected on single dry solid granule on the roller screen, the relative slippage and slipping condition of granule at the tangential direction and axis direction of roller screen are discussed, and the average slipping conveyance velocity from feeding end to discharging end is given. The throwing conveyance of granule is discussed, the throwing coefficientof roller screen and its varying rule, and the concept of average throwing coefficient and its computing method are put forward, the starting condition and terminating condition for throwing motion of granule on the roller screen and the throwing conveyance velocity of granule are researched. The influence on throwing motion of granule by the rotating velocity of roller screen is discussed as well.(3) In terms of flowing characteristic of drilling fluids on the roller screen, the flowing equations at the axis direction and the tangent direction and the flowing through the screen, and the continuously flowing equation of drilling fluids are built. The characteristic-difference equations of flowing model for drilling fluids are given and the theoretical analysis is made.(4) The slipping conveyance model and throwing conveyance model of single wet granule are set up, in turn, computing method of velocity for slipping conveyance and throwing conveyance is given. From the phenomenon of continuously flowing for the real conveyance of wet granule group on the non-submerging roller screen, assuming the granule group as pseudo-fluid, the conveyance model of wet granule group on the non-submerging screen is established. The calculations of all conveyance models are done respectively, pared with data in tests.(5) The author has analyzed the throwing coefficient and the starting throwing condition of granule on the submergi更多还原