定向钻井PDC钻头切削参数计算方法

Computing method for cutting parameters of PDC bit in directional drilling

定向钻井PDC钻头的优化设计和导向性能分析需要准确计算PDC切削齿的切削面积、切削体积和切削弧弧长等切削参数。针对弯外壳螺杆马达或推靠式旋转导向系统,运用空间解析几何理论和数值计算方法,分析了PDC钻头在井底的运动状态,建立了切削齿的运动轨迹方程和切痕曲线方程。综合考虑了钻头偏转角、钻头的复杂运动、钻头结构参数及切削齿切削的先后次序等因素的影响,建立了切削齿的切削面积、切削体积和切削弧弧长等切削参数的数值计算方法,为PDC钻头的计算机优化设计和定向钻井PDC钻头的导向性能分析提供了一种分析手段。实例计算表明,模型和方法具有实用性,可进一步推广应用。

The optimized design of PDC bit for directional drilling and steering performance analysis need accurate calculation of cutting parameters like cutting area, cutting volume and cutting arc length of PDC cutting teeth. In line with different drilling tools-bent housing screw motor or pushing rotational steering system, this paper analyzed the motion status of PDC bit at bottom hole, established the trajectory of cutting teeth and cutting curvilinear equation. Also the numerical computing method was established for cutting area, cutting volume and cutting arc length of the cutting teeth according to bit delfection angle, complex bit motion, bit structure parameters and the sequence of cutting teeth, providing a analysis method for computerized optimal design of PDC bit and the analysis of steering performance of PDC bit. Practical calculation shows that the model and method are practical and can be further promoted.