PDC钻头切削断面对破岩效率的影响

摘要/Abstract

摘要： 基于弹塑性力学和岩石力学，以Drucker-Prager 准则作为岩石的本构关系，采用剪切失效准则，在验证岩石模型及PDC齿破岩建模方法可行性的基础上，建立了PDC齿切削3种典型断面岩石的三维有限元模型，并针对井底不同围压，研究了切削断面的面积、切削齿的后倾角及侧转角对破岩效率的影响。结果表明：不论何种围压，减小切削断面的面积有利于岩石的破碎，且应多采用宽切削断面进行PDC钻头径向布齿；切削齿后倾角对岩石破碎效率影响大于切削齿的侧转角对岩石破碎效率影响，切削齿最优破岩后倾角在低围压下为5°，在高围压下为20°。

关键词: PDC钻头, 切削断面, 破岩效率, Drucker-Prager准则, 数值模拟

Abstract: According to the elastic-plastic mechanics and rock mechanics, the Drucker-Prager criterion was used as the rock constitutive relation and the shear criterion was used to predict damage initiations. Based on the feasibility of rock model and PDC cutter-rock modeling method, a three-dimensional simulation model of cutting shapes rock with a PDC cutter was established, and the influences of cutting areas, the back rake angles and side rake angles of the PDC cutters on rock breaking efficiency were studied for different confining pressures. The results show that reducing the cutting shape areas under any confining pressures is benefit to rock breaking, and the wide cutting shapes may be used in PDC bits. Compared with the side rake angles of the PDC cutters, the back rake angles of the PDC cutters have greater effects on rock breaking efficiency, and the optimal back rake angle is as 5° at low confining pressure and is as 20° at high confining pressures.

Key words: PDC bit, cutting shape, rock breaking efficiency, Drucker-Prager yield criteria, numerical simulation

中图分类号:

TE921

祝效华;易勤健. PDC钻头切削断面对破岩效率的影响[J]. 中国机械工程.

ZHU Xiaohua;YI Qinjian. Influences of Cutting Shapes of PDC Bits on Rock Breaking Efficiency[J]. China Mechanical Engineering.

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