金刚石与磨料磨具工程2025，Vol.45Issue(6)：740-751,12.DOI:10.13394/j.cnki.jgszz.2024.0170
斧形PDC齿破碎非均质花岗岩的数值模拟
Numerical simulation on fragmentation of heterogeneous granite by axe-shaped PDC cutter
摘要
Abstract
Objectives:Polycrystalline diamond compact(PDC)bits are extensively utilized in the drilling industry.However,conventional PDC cutters are prone to failure when drilling through granite formations,leading to reduced drilling efficiency.The axe-shaped cutter,due to its unique geometric structure and stress characteristics,exhibits super-ior performance in drilling such hard formations.Methods:Based on the experimentally determined macroscopic phys-ical parameters of granite,a numerical simulation model for uniaxial compression and the Brazilian splitting test is es-tablished using the Voronoi partitioning method.The integration of experimental data with advanced numerical tech-niques ensures a more precise characterization of the rock's mechanical properties,which is crucial for informing engin-eering applications and improving the understanding of rock failure mechanisms.A comparative analysis of rock-break-ing mechanisms between the axe-shaped cutter and the plane cutter is conducted,investigating the effects of different cutting depths and back rake angles on cutting force,rock-breaking volume,and mechanical specific energy(MSE).Ad-ditionally,the influence of the edge angle of the axe-shaped cutter on rock-breaking efficiency is analyzed through sev-eral indicators.Results:The results indicate that the cutting force increases linearly with the cutting depth,transitioning the rock from ductile to brittle failure and gradually producing block-shaped rock fragments with a lower degree of dam-age,thereby enhancing rock-breaking efficiency.When comparing the MSE of both types of cutters under identical cut-ting depths and rake angles,the specific energy required for rock breaking by the axe-shaped cutter consistently remains lower than that of the plane cutter,indicating that the axe-shaped cutter possesses higher rock-breaking efficiency at the same cutting depth.In comparison to the plane cutter,the axe-shaped cutter exhibits reduced tangential and normal force during the cutting of granite,accompanied by diminished force fluctuations.This reduction in force variability mitigates the probability of cutter damage,thereby extending its operational lifespan.The axe-shaped cutter demonstrates en-hanced capability to penetrate geological formations,requiring lower torque and exhibiting lower specific energy for rock breaking.Furthermore,the average contact stress amplitude during rock cutting is lower for the axe-shaped cutter than for the plane cutter,indicative of superior wear resistance.These attributes collectively underscore the superior per-formance of the axe-shaped cutter in demanding drilling environments,particularly in hard rock formations such as granite.Moreover,under the same rake angle,the axe-shaped cutter experiences a narrower range of force fluctuations,thereby reducing the probability of cutter damage and failure.As the edge angle of the axe-shaped cutter increases,the cutter becomes progressively blunter,with its geometric sharpness gradually decreasing.The force exerted on the cutter exhibits a linear upward trend,while the distribution of stress concentration shows minimal change.Considering both cutting force and specific energy,an axe-shaped cutter with a rake angle of 10°-15° and an edge angle of 110° exhibits high rock-breaking efficiency in granite formations.Conclusions:From both mechanical and rock-breaking perspect-ives,the axe-shaped cutter is more suitable for granite formations compared to the plane cutter.This research provides a scientific basis for selecting axe-shaped cutter parameters for drilling in granite formations,thereby contributing to im-proved drilling efficiency and extended cutter lifespan.关键词
Voronoi图/斧形齿/非均质花岗岩/破岩仿真Key words
Voronoi/axe-shaped cutter/heterogeneous granite/rock-breaking simulation分类
化学化工引用本文复制引用
卢佳俊,张伟,席传明,刘伟吉,张楠..斧形PDC齿破碎非均质花岗岩的数值模拟[J].金刚石与磨料磨具工程,2025,45(6):740-751,12.基金项目
中国石油集团重大科技专项(2023ZZ14). （2023ZZ14）
