Simulation Analysis Of The Performance Of The Oscillation Of The Hydrodynamic Oscillator

In the process of drilling horizontal wells,large displacement wells and lateral wells,due to the complex trajectory of the wellbore,the friction between the drill string and the borehole rock is large,which leads the problems such as sticky card,pressing pressure and low drilling efficiency are often occured.At present,the main method that the problems are solved is using hydraulic oscillators in the process of drilling at domestic and external.Using hydraulic oscillators generated by the pressure pulse drive the drill string axial vibration with low frequency and Small amplitude to make the friction state between the drill string and the borehole rock became a dynamic friction state,which reduces the friction between the drill string and the borehole rock,and solves the problems of the sticky card,the pressing pressure and the drilling efficiency caused by the excessive friction between the drill string and the borehole rock.The hydraulic oscillator consists of Power short section,Valve shaft short section,and Oscillation short section.Power short section and valve shaft short section together make drilling fluid produce the pressure pulse,then oscillating short sections under the action of pressure pulses drive the drill periodically vibrate with axial.there are some problems about the oscillation section in the axial vibration process.Due to choosing the disc spring type and superimposed is not appropriate,which causes the axial vibration amplitude of oscillating short section is too large or too small.if the vibration amplitude is too large,it will bring some vibration damage to the underground drilling tool,or it is too small,which will make the oscillator vibration drag reduction effect is not obvious.The oscillating short section vibration shell directly touch the drilling fluid,and the roughness of the contact surface between the sealing element and the vibration shell is enlarged,which will accelerate the wear of the sealing element,cause the seal structure of oscillation short section failed in advance.In order to solve these problems in a targeted way,this paper uses the finite element analysis software to simulate and analyze the combination and seal structure of the hydrodynamic oscillator short-disc disc spring,and carry out the indoor test of oscillating short section disc spring combination.This article has completed the main work include:Firstly,analyzing the basic structure and working principle of the oscillation section of the hydraulic oscillator,and the working mechanics of oscillating short sections during a vibration cycle,carrying out the force analysis on the combination of the vibrating short section disc spring and the sealing structure,which is the premise that the following content to study disc spring combinations and sealing structures.Secondly,calculating the combination parameters of the oscillating short-disc disc spring of the hydraulic oscillator,and then the combination parameters of disc spring that meet the requirements of axial vibration of oscillating short section are obtained.So establishing a finite element analysis model of the disc spring,obtaining the disc spring combination curve with loading and unloading displacement and determining the combination parameters of the disc spring that satisfying the axial vibration of the oscillating short section.What's more,carrying out the indoor test about the disc spring combination which was obtained by the finite element analysis.then the loading-unloading curve of the disc-spring combination is obtained by using universal test machine do a loading-unloading test for the combination of disc spring,which acquired the loading-unloading curve of the disc-spring combination.Compared with the results of the finite element simulation analysis,Disc spring combination verified the rationality of the finite element model setting.Finally,designing the oscillating short section seal structure,carrying out the finite element analysis of the new seal structure,and analyzing the regularity that compression ratio and external liquid pressure influence on the contact pressure and contact area between the oscillating short section sealing element and the vibration shell,which can provide reference for the design and improvement of the oscillation section structure.Based on the research of the Combined Mode and sealed structure of Oscillator Short-disc Spring for Hydraulic Oscillator,it is can provide some references for the drag reduction efficiency and the service life of the Hydraulic Oscillator Axial Vibration.