摘要
煤层气井射孔环节固井水泥冲击破坏是制约井筒完整性与层间封隔能力的关键,查明固井水泥冲击破坏中的能量耗散特征对优化气井固井水泥体系、改进射孔工艺参数具有实际意义。本研究利用分离式霍普金森压杆装置对煤层气井普通固井水泥、纤维固井水泥试样进行高速冲击加载,结合能量耗散理论对两类固井水泥材料在高速冲击中的能量时程演化、能量分配关系及能量吸收效率影响因素等进行研究,结合试样动态破坏形式特征探讨了冲击能量与材料破坏间的关系。结果表明:(1)相对普通固井水泥,纤维固井水泥吸收能达到平衡较晚,说明普通固井水泥脆断后能量需求减弱,纤维固井水泥由于韧性断裂不彻底后期能量需求依然较高;(2)普通固井水泥冲击破坏形式为脆性破碎,而纤维固井水泥则呈现出均匀断裂破坏特征,纤维增韧效果显著;(3)纤维固井水泥通过界面解离和纤维拉拔效应提升了冲击能量吸收效率,试样破坏程度相对较轻;(4)固井水泥材料冲击下的能量分配与材料结构和强度演化、外部加载条件的量化关系问题值得跟踪关注。
The impact damage of cement of coalbed methane wells is the key to restrict the integrity of wellbore and the ability of interlayer isolation.In this study,impact energy time history evolution,the relationship between the energy distribution and energy absorption efficiency of pure cement,fiber cement were studied using the split Hopkinson pressure bar apparatus,the relationship between impact energy and material damage were analyzed combined with the dynamic damage feature,concluded that:(Ⅰ)fiber cement's absorption energy reaches equilibrium later,indicating that the energy demand of pure cement weakens after brittle fracture,while the energy demand of fiber cement remains high in the later period due to incomplete ductile fracture;(Ⅱ)the impact damage of pure cement is brittle fracture,while that of fiber cement shows uniform fai-lure characteristics,and the toughening effect of fiber is significant;(Ⅲ)the impact energy absorption efficiency of fiber cement is improved through interfacial dissociation and fiber pullout effect,and the damage degree of the sample is relatively light;(Ⅳ)the quantitative relationship between the energy distribution under impact of cementing materials and the evolution of material structure and strength,as well as the external loading conditions is critical.
作者
陈立超
王生维
张典坤
CHEN Lichao;WANG Shengwei;ZHANG Diankun(State Key Laboratory of Coal and CBM Co-mining,Jincheng 048204,China;School of Mining and Technology,Inner Mongolia University of Technology,Hohhot 010051,China;Faculty of Earth Resources,China University of Geosciences,Wuhan 430074,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第S01期232-237,共6页
Materials Reports
基金
山西省煤层气联合研究基金(2016012007)。
关键词
射孔
冲击能量耗散
防冲击
韧性水泥基固井材料
煤层气井
perforation
impact energy dissipation
impact resistant
ductile cement based cementing material
coalbed methane wells
