Research On Technique Of Shock Absorption And Pressure Sensor Using In Continuous Operation Of Test And Measurement Of Petroleum Production

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.