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随着钻头品种的增多，地层优选钻头类型日益受到重视。本文对常用钻头选型方法进行了分析，提出了存在的问题，没有考虑钻井参数对钻头使用效果影响，选型指标缺乏可比性；选型指标单一，不能全面反映钻头使用效果，针对这些问题，作者提出以下改进措施，一是应用多元回归分析方法，从现场钻头使用求出钻头的钻速模式及寿命模式，据此将选型指标实际值转化到某统一钻井条件下的修正值，二是选取与钻头使用效果有关的各指标，应用主成

STUDY ON THE METHOD OF SELECTING BIT

By analysing the methods of selecting bit in common use, the problems of lacking in selection index compare, without considering the influence of drilling parameters on bit service result, selecting single and being unable to overall reflect bit service result are pointed out. Aimed at the problems, the improvement measures of extracting the modes of drilling speed and operating life of the bit from field data by multiple regression analysis, then, turning the selection index actual value into the corrected value in some unified drilling condition and selecting the indexes being relative to bit service result as the final selection indexes are proposed out. The computation analysis of the bit service data in some areas of Jianghan Oil Field shows that the selection result is reasonable and the method is available. The problems of selecting bit by drilling parameters and rock drillability are also discussed.