摘要
通过引入纳米压痕技术研究了川南龙马溪组页岩的微观力学性质。定量化研究了页岩脆性颗粒和有机粘土复合体以及不同纹层的弹性模量和硬度,分析了影响其微观力学性质的主控因素。研究结果表明:页岩中不同矿物、不同纹层之间的力学性质差异较大,其微观力学性质的差异性来自于自身的成分、构造以及强烈的非均质性。其中脆性矿物颗粒的弹性模量和硬度最大,有机质粘土复合体颗粒的最小;纹层的力学性质介于两种颗粒之间,富含碎屑颗粒的纹层要高于富含粘土颗粒的纹层;页岩中矿物颗粒的弹性模量与硬度之间存在正相关性,而纹层的弹性模量随硬度的增大呈非线性增大。影响页岩力学性质的因素可分为两类,分别是软组份和硬组份两类,弹性模量和硬度与软组份之间存在负相关性,与硬组份呈正相关。
The microscopic mechanical properties of shale taken from Wufeng formation and Longmaxi formation in south Sichuan area were studied by introducing nano-indentation technique.The elastic modulus and hardness of shale brittle particle,organo-clay complex and different bedding planes were quantitatively studied.The main controlling factors affecting their micromechanical properties were analyzed.Study results show that there are great differences in mechanical properties among different minerals and bedding planes in shale.The difference of micromechanical properties comes from their own composition,structure and strong heterogeneity.Among them,the elastic modulus and hardness of brittle mineral particles are the largest,and that of organic-clay complex particles are the smallest,the mechanical properties of bedding planes are between two kinds of particles,and elastic modulus and hardness of bedding planes rich in clastic particles are higher than that of rich in clay particles.There is a positive correlation between elastic modulus and hardness of mineral particles in shale,but the elastic modulus of bedding planes increases nonlinearly with the increase of hardness.The factors affecting the mechanical properties of shale can be divided into two categories:soft component and hard component. There is a negative correlation among elastic modulus,hardness and soft component,and a positive correlation among elastic modulus,hardness and hard component.
引文
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