PDC钻头切削表面流场携岩能力分析

ANALYSIS OF SOLID CARRYING CAPACITY OF SURFACE FLOW FIELD OF PDC BIT

针对PDC钻头泥包问题,分析了钻头表面岩屑运移的原理。利用计算流体力学的理论和方法,建立了PDC钻头表面流体的流动方程和钻头冠部三维数据体模型。通过数值计算和数据分析,研究了钻头岩屑的起动条件,钻头冠部流体速度、压力分布等值线,形成了PDC钻头水力设计的基本原则。研究PDC钻头冠部速度流场分布是解决钻头表面岩屑颗粒起动而不产生泥包的直接途径。

Aiming at the balled-up PDC bit problem,the cuttings migration mechanism at the bit surface was analyzed.By using the theory and method of computational fluid mechanics,the flow equation of the surface fluid on PDC bit and 3-D data volume model of the bit crown were established.The paper put forward the basic principles of PDC bit hydraulics design based on numerical calculation and data analysis as well as research of activation condition of cuttings,fluid velocity at bit crown,pressure distribution contour.The research on fluid velocity distribution at PDC bit crown could solve the problem of balled-up bit.