Abstract: Based on the previous research, this paper establishes the relationship between the dewatering transformation of the clay minerals and the diagenetic stages and the formation of pore fractures. The influence of temperature, time, pressure, pore fluid properties and thermal evolution of organic matter on the transformation of clay minerals is summarized. By comparing the paleogeotemperature in the transformation of various clay minerals and change of fluid properties, the diagenesis evolution of shale is divided into three stages, and the difference of main diagenetic reaction in each stage leads to the variance of mineral assemblage.The adsorption capacity of methane is closely related to the transformation of clay minerals in shale diagenesis.The experimental results show that the order is smectite>illite/smectite mixedlayer>kaolinite>chlorite>illite. Illitization of smectite and chloritization of smectite are important diagenetic reactions, and the study and establishment of their genetic mechanism model have a certain reference significance for the study of shale reservoir.

Key words: Diagenetic evolution, Clay minerals, Dehydration, Thermodynamic mechanism

摘要： 在总结前人相关研究基础之上,建立了黏土矿物脱水转化与成岩阶段划分、孔隙裂缝形成的关系,总结了温度、时间、压力、孔隙流体性质以及有机质热演化对黏土矿物转化的影响。通过对比各种黏土矿物转化时的古地温和流体性质变化,将泥页岩成岩演化划分为3个阶段,每个阶段发生的主要成岩反应不同,致使矿物组合发生差异。实验结果显示,甲烷吸附能力大小与泥页岩成岩过程中黏土矿物转化密切联系,其相对大小顺序为:蒙脱石 >伊蒙混层>高岭石>绿泥石>伊利石。蒙皂石伊利石化和蒙皂石绿泥石化是较为重要的成岩反应,探讨他们的成因机制,并建立相应模型,对研究泥页岩储层有一定的参考意义。

关键词: 成岩演化, 黏土矿物, 脱水作用, 热动力机制