牙轮钻头轮头速比理论研究及其仿真模型

牙轮钻头在破岩的过程中,影响牙轮转速的因素非常复杂。牙轮钻头的轮头速比研究对岩石破碎机理研究和钻头设计都有重要的指导意义。牙轮钻头轮头速比模型是钻头-岩石互作用仿真中最重要的基础模型之一。总结了国内外以基于正交试验结果回归、力矩平衡、最小功原理等为代表的几种牙轮钻头轮头速比模型建模理论,对比分析了这些理论的优点及存在的问题。在分析影响轮头速比的几何结构、钻井参数的基础上,提出了基于转动定律的轮头速比仿真模型。该模型综合考虑了影响轮头速比的主要因素,避免了计算牙齿受力、能客观真实地反映轮头速比的数值大小及变化规律,为进一步优化牙轮钻头钻进仿真模型奠定了基础。

A Theoretical Study of the Velocity Ratio of the Cone Bit Head and Its Simulation Model

The factors influencing cone rotation are very complex in the rock-breaking process of cone bit.Research on the velocity ratio of cone bit head is of vital importance to the study of rock-breaking mechanism and bit design.The velocity ratio model of cone bit head is one of the most important basic models in simulation of bit-rock interaction.Several typical modeling theories of cone bit head velocity ratio at home and abroad were summarized,which are based on result regression of orthogonal test,torque balance and minimum work.A comparative analysis of the theories was conducted to deal with their strengths and existing problems in them.The simulation model of cone bit head velocity ratio based on the law of rotation was proposed on the basis of analysis of the geometric structure and drilling parameters which affect the cone head velocity ratio.The model makes a comprehensive consideration of the main factors of influence value and avoids the calculation of tooth force.It can reflect the size of the cone head velocity ratio value and variation law in an objective and realistic way,laying the foundation for the further optimization of the simulation model of cone bit drilling.