摘要
对高压电脉冲破碎机制的研究是提高钻井破岩效率和优化电脉冲电参数的关键。利用颗粒流离散元软件及Voronoi划分建立非均匀介电性质的花岗岩模型,从电流场、电路场、电击穿场进行等离子通道生长过程仿真,并分析非均质度对击穿路径的影响;对比不同花岗岩的电破岩效率和电脉冲破岩效果。结果表明:花岗岩的非均质度增大使得初始电场极值增大,相应地降低了电破岩的能量需求;等离子通道的生长方向存在优先发展区域,等离子通道的生长过程体现出通道尖端处电场集中现象强于通道躯干处;花岗岩非均质度的差异使得等离子通道的总长度和平均贯穿深度存在显著差异,在一定非均质度范围内电脉冲破碎效果和非均质度呈正相关;不同非均质度花岗岩的单脉冲电破岩效率差异不大,等离子通道的总长度越长,电破岩效率越高。
A detailed understanding of the fragmentation mechanism by the high-voltage electrical pulses(HVEP)technology is essential to enhance ROP in rock-breaking and to optimize the electrical parameters.The particle flow code(PFC)software and Voronoi tessellation were used to generate granite models with non-uniform dielectric properties.The plasma channel growth process was simulated from the current field,the circuit field and the electric breakdown field,and also the influence of heterogeneity on the breakdown path was analyzed.The HVEP rock-breaking efficiency and the electric pulse rock-breaking effect of different granites were compared.The results show that the increase of heterogeneity of granite increases the initial electric field’s extreme value,and correspondingly reduces the energy demand of electric rock breaking.There is a preferential development region in the growth direction of the plasma channel,and the growth process of the plasma channel shows that the electric field concentration at the tip of the channel is stronger than that at the trunk of the channel.The difference in the heterogeneity of the granites results in significant difference in the total length and the average penetration depth of the plasma channels.In the range of a certain degree of heterogeneity,the HVEP crushing effect is positively correlated with the degree of heterogeneity.The single-pulse electric rock breaking efficiency of different heterogeneity granites has little difference.The longer the total length of the plasma channel,the higher the electric rock breaking efficiency is.
作者
祝效华
陈梦秋
刘伟吉
ZHU Xiaohua;CHEN Mengqiu;LIU Weiji(School of Mechatronic Engineering,Southwest Petroleum University,Chengdu 610500,China;Key Laboratory of Petroleum and Natural Gas Equipment,Ministry of Education,Chengdu 610500,China;Geothermal Energy Research Center,Southwest Petroleum University,Chengdu 610500,China)
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第5期151-159,共9页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家自然科学基金项目(52225401,52034006)。
关键词
电脉冲破岩
非均质花岗岩
电击穿
等离子通道钻井
钻井提速
electric pulses rock-breaking
heterogeneous granite
electric breakdown
plasma channel drilling
rate of penetration
