Experimental study on the mechanical behavior of high-stress rocks during real-time drilling
Zhichao He1
Fengqiang Gong2
Mingzhong Gao3
1.School of Civil Engineering,Southeast University,Nanjing 211189,People's Republic of China2.School of Civil Engineering,Southeast University,Nanjing 211189,People's Republic of China;Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization,Shenzhen University,Shenzhen 518060,People's Republic of China3.Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization,Shenzhen University,Shenzhen 518060,People's Republic of China
摘要：The formation of a pressure relief zone is crucial for rockbust prevention during drilling pressure relief.This study investi-gates the mechanical behavior of high-stress rock under real-time drilling conditions and elucidates the mechanism behind the creation of the pressure relief zone.Utilizing the independently developed SG4500 drilling rig,we conducted a theoreti-cal analysis of the forces acting on the drill bit.The analysis showed that cutting depth is directly proportional to real-time drilling speed,while tangential and normal forces are influenced by drilling diameter.Uniaxial compression tests on red sandstone specimens under high-stress real-time drilling conditions examined the impacts of different drilling speeds(800,400,100 r/min)and diameters(6,8,10,12 mm)on rock mechanical behavior,rockburst characteristics,crack evolution,and peak elastic strain energy.The results indicate that decreasing drilling speed and increasing drilling diameter weaken rock mechanical behavior,including peak strength,Young's modulus,rockburst characteristics,and peak elastic strain energy.Crack evolution analysis reveals that smaller drilling diameters and higher drilling speeds promote the development of far-field cracks,while larger drilling diameters and lower drilling speeds lead to crack formation around the borehole,and significantly affecting rock failure mechanisms.Theoretical analysis further confirms the correlation between crack evolution and stress distribution surrounding the drilling.Under vertical stress,the cracks near the borehole formed during real-time drilling are mainly influenced by tangential compressive and tensile stresses.Overall,this study provides a new perspective on understanding the mechanisms of drilling pressure relief for rockburst prevention.
机标关键词：real-timebehaviorrocksstudydrillingduringexperimentalhigh-stress
论文发表日期：2025-06-30
在线出版日期：2025-10-15（本平台首次上网日期，不代表文献的发表时间）
页数：23( 98-120 )
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