摘要
为揭示富有机质页岩水化损伤机理,以长宁地区龙马溪组页岩为研究对象,借助于XRD衍射、自吸、浸泡、水化应力、水化应变等一系列物理试验,对其水化特征进行了研究。实验结果表明:富有机质页岩以黏土矿物和石英为主,黏土矿物中伊利石和伊蒙混层为主要成分,无蒙脱石;自吸水过程中会发生水化作用,且黏土矿物含量越高,自吸水量越大,水化反应越易发生;水化作用前期较剧烈,后期逐渐趋于稳定;水化过程中可观察到裂纹的萌生、扩展和汇合现象,进一步演化为宏观贯穿裂纹。黏土矿物中伊利石的线性水化应力稍小于蒙脱石,但水化应变却远小于蒙脱石。不同黏土矿物、混层矿物的水化不均匀导致富有机质页岩发生水化损伤现象。
In order to reveal the hydration damage mechanism of organic-rich shale, the hydration characteristics of Longmaxi shale in Changning area were studied by means of XRD diffraction, spontaneous imbibition, immersion, hydration stress, hydration strain and other physical experiments. The results show that the organic-rich shale is mainly composed of clay minerals and quartz, and the main composition of clay minerals is illite and illite smectite mixed layer, without montmorillonite. Hydration occurs during the process of self-water absorption of organic-rich shale, and the higher the content of clay minerals, the greater the spontaneous imbibition, the more likely hydration reaction occurs. The hydration of organic-rich shale is more intense in the early stage of the reaction and gradually tends to be stable in the later stage. The initiation, expansion and confluence of cracks in the hydration process could be observed and they gradually evolved into macro-penetrating fractures. The linear hydration stress of illite is slightly less than that of montmorillonite, but the hydration strain is much less than that of montmorillonite. The non-uniform hydration of different clay minerals and the mixed layers leads to the hydration damage phenomenon of organic-rich shale.
作者
王跃鹏
刘向君
熊健
梁利喜
Wang Yuepeng;Liu Xiangjun;Xiong Jian;Liang Lixi(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2022年第3期891-900,共10页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(41772151)
国家自然科学基金联合基金重点项目(U1262209)。
关键词
富有机质页岩
自吸
伊利石
蒙脱石
水化应力
水化应变
organic-rich shale
spontaneous imbibition
illite
montmorillonite
hydration stress
hydration strain
