It is based on a database of past PDC bits.In the databased,it includes bit type,average shear stress of well which bit was used in,cost per unit length.

• 该方法以一个建成的PDC钻头使用资料库为基础 ,该数据库包括钻头型号、所钻井段地层的平均剪切强度、单位进尺钻井成本等指标。