基于旋转侵入理论的牙轮钻头钻速模型

 针对旋转钻井牙轮钻头对井底岩石垂向压入和水平刮切联合作用的特点, 基于牙轮钻头旋转侵入理论, 建立了机械钻速预测模型, 并通过室内实验确定了楔形齿纯滚动多齿联合作用对破岩效果的综合影响系数, 机械钻速预测平均误差为4.1%。研究认为, 考虑钻头旋转引起的水平刮切力时, 侵入深度比只考虑垂向压入时有所增加;摩擦系数和刃尖角较小时两者相差不大, 随着摩擦系数和刃尖角的增大, 两者的相对差值越来越大, 摩擦系数和刃尖角较大时钻头旋转引起的水平刮切作用对机械钻速的影响不容忽视。

Penetration rate model of roller bit based on revolving indentation theory

The roller bit acts on the bottom hole rock jointly by a vertical indentation and a level shave shear during the rotary drilling. For its analysis, this paper establishes a prediction model for the rate of penetration based on the revolving indentation theory of the roller bit, and through the laboratory tests, obtains the influence coefficient for rock breaking caused by the chisel teeth true rolling pluridentate linkage. The prediction error for the rate of penetration is 4.1% in average. The model provides a theoretical basis for the accurate prediction of the rate of penetration of the roller bit in the rotary drilling. It is concluded that, taking the level shave shear force into consideration, the intrusive depth of the roller bit is increased as compared with the case of only vertical pressing. The difference is smaller for the case of small frictional coefficient and cutting tip angle. However, it becomes greater with the increase of the frictional coefficient and cutting tip angle, so the effect of the horizontal scrapping cannot be ignored.