流体介质对高速涡轮钻具力学性能影响研究

提高涡轮钻具的力学性能一直是涡轮钻具研究的主要内容。为此,以178 mm高速涡轮钻具为原型,在台架试验的基础上,利用CFD方法,研究了不同介质密度、不同介质黏度对涡轮钻具力学性能的影响。研究和试验结果表明,随着介质密度的增加,高速涡轮钻具的压降、工作转速对应的扭矩及输出功率均会增大,介质黏度的改变对高速涡轮钻具的扭矩和输出功率基本无影响。在进行涡轮钻具设计时,应该考虑其对流体介质物理性质变化的适应能力,合理设计工作转速范围。现场使用涡轮钻具,当钻井液密度、黏度发生改变时,应注意调整泵压、钻压以保证最佳工况。

Research on the Effect of Fluid Media on the Mechanical Property of High Speed Turbo-drill

Improvement of the mechanical property of turbo-drill has always been the main content of turbo-drill research.Taking as the prototype the 178 mm high speed turbo-drill and applying the CFD method,the effect of the density and viscosity of different media on the mechanical property of turbo-drill was studied on the basis of bench test.The research and experimental findings show that when the medium density rises,the turbo-drill pressure will drop and the torque and output power corresponding to the operating rotary speed will increase.The change of the medium viscosity basically has no effect on the torque and output power of the turbo-drill.The adaptability of the physical property change of fluid medium should be considered in designing turbo-drill and the scope of operating rotary speed should be designed reasonably.In field application of the turbo-drill,the pump pressure and WOB should be adjusted in order to ensure the optimum operating condition when the density and viscosity of drilling fluid change.