摘要
基于有限元-离散元方法,建立并验证轴向冲击破岩的三维数值模型,提出冲击破岩过程中能量转换计算方法,分析锥齿前倾角、岩石温度与冲击速度对岩石破碎特征及能量传递规律的影响。研究表明:(1)单次锥形齿钻头冲击破岩时,仅7.52%~12.51%的能量用于破碎岩石,而57.26%~78.10%的能量因摩擦损耗未能有效利用;(2)前倾角过小,会增加锥齿吃入深度以及摩擦损耗,前倾角过大会降低锥齿的吃入能力,钻头将反弹并使冲杆吸收更多能量,锥齿前倾角存在最优值。(3)高温可显著增强岩石的冲击破碎效果,但高温造成的热损伤会降低岩石的强度,抑制岩石对能量的吸收;(4)高冲击速度能加剧岩石的破坏程度,但冲击速度过高,摩擦损耗增加,岩石吸收能量占比下降,岩石破坏程度并不能大幅提升,冲击速度也存在最优值。
Based on the finite-discrete element method,a three-dimensional numerical model for axial impact rock breaking was established and validated.A computational method for energy conversion during impact rock breaking was proposed,and the effects of conical tooth forward rake angle,rock temperature,and impact velocity on rock breaking characteristics and energy transfer laws were analyzed.The results show that during single impact rock breaking with conical tooth bits,merely 7.52%to 12.51%of the energy is utilized for rock breaking,while a significant 57.26%to 78.10%is dissipated as frictional loss.An insufficient forward rake angle increases tooth penetration depth and frictional loss,whereas an excessive forward rake angle reduces penetration capability,causing bit rebound and greater energy absorption by the drill rod.Thus,an optimal forward rake angle exists.Regarding environmental factors,high temperatures significantly enhance impact-induced rock breaking.Thermal damage from high temperatures reduces rock strength and inhibits its energy absorption.Finally,higher impact velocities intensify rock damage,yet excessively high velocities increase frictional loss and reduce the proportion of energy absorbed by the rock,thereby failing to substantially improve rock breaking efficiency.An optimal impact velocity exists.
作者
刘清友
黄涛
LIU Qingyou;HUANG Tao(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;College of Energy,Chengdu University of Technology,Chengdu 610059,China)
出处
《石油勘探与开发》
北大核心
2025年第4期930-938,共9页
Petroleum Exploration and Development
基金
国家自然科学基金重大仪器项目“井下机器人智能钻完井模拟实验系统研制”(52327803)
国家自然科学基金重大项目课题“开采过程多场时空演变规律与流动调控方法”(52192622)。
关键词
干热岩
有限元-离散元方法
锥形齿钻头
前倾角
冲击速度
岩石温度
能量传递
破岩机理
hot dry rock
finite-discrete element method
conical tooth bit
forward rake angle
impact velocity
rock temperature
energy transfer
rock breaking mechanism
作者简介
第一作者:刘清友(1965-),男,重庆开县人,博士,成都理工大学教授,主要从事石油钻头装备理论、实验、产品与应用研究。地址:四川省成都市成华区二仙桥东三路1号,成都理工大学,邮政编码:610059。E-mail:Liuqy66@aliyun.com。
