摘要
复合冲击破岩技术的研究目前多聚焦于不同钻井参数对破岩效率的影响,而对裂纹扩展及岩屑生成机制的理解仍显不足,限制了该技术的进一步发展。针对深部地层中复合冲击破岩机理尚不完善的现状,文章基于离散元方法建立了PDC钻头的单齿复合冲击破碎非均质花岗岩模型,分析了在破碎花岗岩过程中切削深度、冲击幅值、围压、冲击频率以及冲击角度对复合冲击破岩的影响。研究表明,在复合破岩过程中,岩石经历拉-剪复合破坏,且适宜在切削深度小于0.8mm时使用;轴向冲击频率、幅值大于扭转冲击时能取得较好的破岩效果。在本研究中,扭转与轴向冲击幅值比为0.1~0.3、扭转与轴向冲击频率比为1∶4时破岩效率最高,若综合破岩效率与钻齿寿命,建议采用2∶1的频率比。研究还发现随着冲击角度的增大,复合冲击钻井的能耗呈上升趋势,且在冲角为30°时,破岩效率最高。文章的研究结果为复合冲击钻具的设计和优化提供了重要的技术参考。
Research on composite impact rock-breaking technology has mainly focused on the influence of various drilling parameters on rock-breaking efficiency.However,the understanding of crack propagation and rock debris generation mechanisms remains insufficient,limiting the further development of this technology.In response to the incomplete understanding of composite impact rock-breaking mechanisms in deep strata,this paper establishes a discrete element model for single-cutter composite impact breaking of heterogeneous granite.The study analyzes the effects of factors such as cutting depth,impact amplitude,confining pressure,impact frequency,and impact angle on composite impact rock breaking.The results show that,during the composite rock-breaking process,the rock undergoes tensile-shear combined failure,with optimal performance observed when the cutting depth is less than 0.8 mm.When the axial impact frequency and amplitude are greater than those of torsional impact,better rock breaking effects can be achieved.In this study,the highest rock-breaking efficiency is obtained when the amplitude ratio of torsional to axial impact is 0.1-0.3 and the frequency ratio is 1:4.Considering both rock-breaking efficiency and drill tooth life,a frequency ratio of 2:1 is recommended.The study also finds that as the impact angle increases,the energy consumption of composite impact drilling rises,with the highest rock-breaking efficiency occurring at an impact angle of 30°.The findings provide important technical references for the design and optimization of composite impact drill tools.
作者
刘玉明
李志彬
刘禹铭
韩雪银
宋学锋
丁意达
王燕飞
刘伟吉
LIU Yuming;LI Zhibin;LIU Yuming;HAN Xueyin;SONG Xuefeng;DING Yida;WANG Yanfei;LIU Weiji(CNOOC EnerTech-Drilling&Production Co.,Ltd.,Tianjin 300452,China;State Key Laboratory of Offshore Oil Exploitation,Tianjin 300459,China;Southwest Petroleum University,Chengdu,Sichuan 610500,China)
出处
《钻采工艺》
北大核心
2025年第4期37-47,共11页
Drilling & Production Technology
基金
国家自然科学基金“深层干热岩钻进井壁围岩宏细观破裂机理及稳定性控制研究(编号:52274231)
中国海油能源发展工程技术公司科研项目“硬地层裸眼一趟式侧钻工艺及配套工具研究”(编号:GCJSXMHT-2314)。
