一种PDC钻头选型新方法研究

A NEW METHOD OF PDC BIT SELECTION

介绍了利用剪切强度和单位进尺钻井成本的关系来进行PDC钻头选型的新方法。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。在选型时 ,通过所钻区块邻井的测井资料计算出不同井深各间隔点的地层剪切强度 ,从需要进行钻头选型的井段开始 ,确定计划钻井段地层剪切强度的平均值。以此平均值为基点 ,在合理的偏差范围内 ,从数据库中选择PDC钻头 。

This paper presents a method to select PDC bits.This method uses a correlation between shear strength and drilling cost estimation per unit length.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.When selecting PDC bits,we concern the well to be drilled.Using correlation wells,the sonic log response is estimated for the well of interest.Shear stress is calculated and plotted versus depth.The shear stress is selected and its average value is determined.Then we can select all bits within PDC bits database that have average shear stress restricted within a selected limit through computer program.The bit that yields the cheapest cost per meter is the best choice.And the paper is also presents examples of selection PDC bits.