摘要
在深部高应力地层钻孔取心过程中,岩心因扰动和应力释放效应而表现出显著的饼化破坏特征。本文以四川盆地深达1800 m的三叠纪地层钻探样本为研究对象,通过宏观观察与微观分析相结合的方法,系统揭示了浅部与深部围岩岩心饼化现象的差异及其形成机理。研究发现,浅部岩心的非均匀饼化特征由钻孔爆破扰动引发的随机损伤效应主导,而深部岩心的均匀薄饼化则反映了原位地应力释放的内在作用。此外,钻孔直径和岩心晶粒特性对饼化现象具有显著影响,大直径钻孔与粗晶粒岩心更易形成较厚的饼化岩心。通过数值模拟交叉试验量化分析,揭示了水平与垂直应力对裂隙扩展及能量演化的不同作用,进一步验证了饼化现象与原位应力条件的紧密关联。研究发现:水平应力对裂隙扩展的促进作用显著,而垂直应力对饼化现象具有一定的抑制作用。本研究从宏观破坏形貌到微观机理阐释了岩心饼化现象及其应力特征,为深部地质钻探与资源开发工程及技术优化提供参考。
During the process of coring in deep high-stress strata,the core exhibits significant disk-shaped damage characteristics due to disturbance and stress release effects.In this paper,taking the drilling samples from Triassic strata in Sichuan Basin at a depth of 1800 m as the research object,through a combination of macroscopic observation and microscopic analysis,the differences in the disk-shaped damage of shallow and deep surrounding rock cores and their formation mechanisms have been systematically revealled.It is found that the non-uniform disk-shaped damage characteristics of shallow cores are dominated by the random damage effect caused by drilling and blasting disturbance,while the uniform thin disk-shaped damage of deep cores reflects the intrinsic effect of in-situ stress release.In addition,the diameter of the borehole and the grain characteristics of the core have a significant impact on the disk-shaped damage behavior,with larger diameter boreholes and coarser-grained cores more likely to form thicker disk-shaped damaged cores.Through quantitative analysis of cross experiments of numerical simulation,different effects of horizontal and vertical stresses on crack propagation and energy evolution have been revealled,and close relationship between the disk-shaped damage phenomenon and in-situ stress conditions have been verified.The study clarifies that the horizontal stress significantly promotes crack propagation,while the vertical stress has a certain inhibitory effect on the disk-shaped damage phenomenon.The core disk-shaped damage phenomenon and its stress characteristics from macroscopic damage morphology to microscopic mechanism have been explained.It will provide insights and technical optimization suggestions for deep geological drilling and resource development engineering.
作者
徐克全
李海波
毕叶岚
XU Kequan;LI Haibo;BI Yelan(No.5 Exploration Brigade of Shandong Coalfield Geology Bureau,Shandong Ji'nan 250104,China)
出处
《山东国土资源》
2026年第2期50-58,共9页
Shandong Land and Resources
基金
国家自然基金联合基金项目U23A20601。
关键词
地质钻探
岩心饼化
力学机理
能量演化
Geological drilling
disk-shaped core
mechanical mechanism
energy evolution
