【作者】 崔之健；

【导师】 陈传尧； 胡元太； 王元勋；

【作者基本信息】 华中科技大学 ， 工程力学， 2007， 博士

【摘要】 把地层射孔和地层数据测试有机联系在一起的测试联作技术,是石油工程中的一项新的施工技术。为了准确测出原始地层压力并防止射孔造成的冲击波对测试仪器产生损害,迫切需要对测试联作中的减振器和压力传感器进行研究。本文基于行波法分析井下测试管柱的减振模型,基于有限元软件ANSYS/LS-DYNA研究冲击载荷下石油测试管柱减振系统的动力学性质。在模拟过程中涉及几何非线性、材料非线性、状态非线性和动态加载等问题。最后利用小增量场理论,对压力传感器的工作原理以及灵敏度的改善进行了分析。本文主要研究工作体现在以下几个方面:(1)考虑上层管柱从减振器系统的吸能效果,建立了适合分析长测试管柱冲击载荷下减振问题的模型——行波法模型,分析了长测试管柱的材料参数对减振效果的影响。得到了选择较大的折合阻力系数(上层管柱材料系数和减振器参数比值)α,可以增强减振效果等有意义的结论。(2)建立了新设计研制的减振器和以往现场用的减振器三维有限元模型,并藉此进行了仿真计算,讨论了在冲击强度一定的条件下,三种不同主瓣频率的半正弦脉冲力对减振效果的影响,通过减振器减振效果的比较,新型减振器的减振效果很好,尤其是在中高频段。(3)对已建立的新型减振器模型,采用有限元系统研究了弹簧刚度、橡胶Mooney-Rivlin参数、橡胶和外套管的动摩擦系数、下接头质量以及脉冲力的冲击强度和冲击波形对系统减振效果的影响。(4)采用均匀设计法,选取新型减振器的24组不同结构参数,建立了三维有限元分析模型,用LS-DYNA计算减振系统的最大位移和最大地基扰动力分布情况,然后对最大位移和最大地基扰动力进行多元线性回归,得到了最大位移和最大地基扰动力影响因素的拟合特性。(5)对西安213所出产的液压、橡胶减振器和新型减振器进行了动态模拟实验,将实验结果与有限元分析计算结果进行比较,验证了有限元分析结果的正确性。(6)分析了几类常见的基于偏场原理而设计的压力传感器,分别得到了面内偏场与频率漂移的表达式。考虑到压电板的面内刚度远大于弯曲刚度,为了提高这类基于偏场原理而设计的压力传感器的灵敏度,最后计算分析了初始场或偏场对力电耦合因子的影响。更多还原

【Abstract】 Continuous Operation of Test and measurement is a new operating technique in petroleum production,which combines perforation with test and measurement effectively. In order to measure the original pressure of stralayer exactly and prevent testing instrument from impairation,it is urgently necessary to research a suitable shock absorber and pressure sensors.Base on traveling wave method,a model is set up to analyse vibration of a tubular column for continuous operation of test and measurement of the petroleum production.Dynamic characters of shock absorber system for well testing tubular column under impact load were researched which were based on finite element analysis software ANSYS/LS-DYNA.Geometry nonlinear,material nonlinear,state nonlinear and dynamic load are involved in the analysis.By using the theory of small fields superposed on finite biasing fields in an electroelastic body,the principle of pressure sensor and its sensitivity are researched.Several aspects such as follows are discussed in this paper:(1) Considering effect of topper long column absorbing energy from shock absorber system,model basing on traveling wave method has been proposed,which suits to analyze problem on absorbing vibration of long column of test and measurement under shock load. It is found that bigger aspect ratioα,i.e.ratio of material coefficient of topper long column to parameters of shock absorber,can strength effect of damping on vibration.(2) Establish 3D finite element model of new designed shock absorber and local shock absorber former used,and simulating calculation is also carried on with this model, discuss the effect of shock absorber impact by half sinusoidal pulse force under three different main lobe frequencies.After comparation,we found performance of the new type shock absorber is better than the old one,especially under the middle and high frequencies.(3) The new type of shock absorber are simulated by change spring rigidity,rubber Mooney-Rivlin parameter,dynamic friction coefficient of rubber,outer cannula and the mass of lower contact.The effects of these parameters to the shock absorber are discussed. By changing work condition,impact strength and waveform of pulse force,the effects of the new shock absorber are analyzed respectively.(4) A 3D finite element analysis model was established by adopting uniform design method with twenty-four groups of different structural parameters of the new type shock absorber.The maximum displacement and distribution of the soil-structure maximum disturbing force for the shock absorber system were calculated with LS-DYNA.The multivariate linear regression was performed on the maximum displacement and the maximum soil-structure disturbing force.The fitting property of seven influence factors act on the maximum displacement and the maximum soil-structure disturbing force was obtained.(5) By doing signal input and output attenuation experiment on long and short shocker absorber of xi’an 213 graduate school and new type of shock absorber,their shock absorber coefficient are compared.The new type of shock absorber is simulated and analyzed with finite element method,and then compared it with experiment result.(6) After analyzing on some kinds of common pressure sensors base on biasing field principle,expressions between in-plane biasing field and frequency shift have been obtained.Because in-plane stiff of piezoelectric plate is much higher than that of flexural stiff,in order to improve sensitivity of this kind of pressure sensor which base on biasing field principle,this paper futher analyze a type pressure sensor which is designed basing on flexural biasing field.Charaters of pressure sensor are computed which under three common bending modes of pure bending,bending under a concentrate load,and bending under a uniformly load.At last,we study effects of initial or biasing fields on electromechanical coupling factors of electroelastic materials.更多还原