基于IADC编码量化的牙轮钻头选型模型

Model for Roller Bit Selection Based on IADC Code Quantification

合理的钻头选型是提高机械钻速和降低钻井综合成本最直接的方式之一,开发牙轮钻头选型系统的主要目的是为钻井工程中钻头的选择提供可靠的技术支持。基于测井数据解释理论模型研究成果,提出了牙轮钻头IADC编码量化的方法。针对地层抗压强度级值的不同范围将牙轮钻头分为首选型号、可接受型号和拒绝型号3种类型,建立了牙轮钻头适用系数量化模型。利用该模型,在对井段进行抗压强度值统计的基础上,得到适用于该井段的钻头综合适用系数曲线,据此推出该井段牙轮钻头的IADC编码量化值。实例验证结果表明,计算得到的地层岩性组分剖面与录井图较为符合,同时推荐的钻头型号与实际使用钻头型号相比更为合理。建立的钻头选型方法为牙轮钻头的优选提供了一种新的技术手段。

Selection of optimal drilling bit is one of the most direct ways to enhance R0P and reduce overall drilling costs. The system for selection of roller bits was developed to provide reliable technical supports for bit se- lection. Based on the research results related to theoretical model for interpretation of logging data, a method based on quantification of IADC codes for roller bits was proposed. In accordance with different extents of formation strengths, roller bits were classified into three categories： preferred, acceptable and rejected. Quantification model for applicability factors of roller bits was established. By using the model, plots for comprehensive applicability fac- tors of bits suitable for the interval with statistics related to formation strength in the interval. In this way, IADC codes of roller bits available for the interval were clarified. Application performances showed that formation lithologie profiles determined through calculation coincided well with logging plots. In addition, recommended bits are more suitable than those actually deployed.