连续波脉冲器发生原理及参数影响规律研究

连续波脉冲器是随钻测量的核心部件。为了探讨连续波脉冲器压力波发生原理及参数影响规律,基于计算流体力学相关理论与方法,建立了连续波脉冲器流场数值仿真模型,仿真分析了连续波脉冲器的流场特征。仿真结果表明:转子周期性往复开关过程中,连续波脉冲器产生流量波和压力波,流量波上、下游相位相同,压力波上、下游相位相反;压力波幅值与脉冲器控制参数相关,幅值随频率与定转子间隙的增大而减小;压力波幅值与钻井水力参数相关,随流体排量和密度的增大而增大,流体黏度对幅值影响可以忽略。研究结果对连续波脉冲器的现场应用具有一定的理论指导作用。

Research on Generation Principle and Parameter Influencing Law of Continuous Wave Pulser

Continuous wave pulser is a core component of the measurement-while-drilling( MWD) tool. In order to discuss the principle of pressure wave generation of the continuous wave pulser and the influencing laws of its parameters,a numerical simulation model of flow field of the continuous wave pulser was established based on relevant theories and methods of computational fluid dynamics( CFD),which was used to simulate the characteristics of flow field of the continuous wave pulser. The numerical simulation results showed that,in the cyclic reciprocating switching process of the rotor,the continuous wave pulser will generate flow wave( the upstream and downstream phase positions are same) and pressure wave( the upstream and downstream phase positions are opposite);the amplitude of pressure wave is related to the pulser control parameters,which will decrease with the increase of frequency and stator-rotor clearance;the amplitude of pressure wave is related to the hydraulic parameters for drilling operation,which will increase with the fluid discharge capacity and density,and the influence of fluid viscosity on the amplitude is negligible. The study results will has theoretical guiding significance for the field application of continuous wave pulsers.