基于热模拟实验的泥页岩黏土矿物演化及成岩阶段划分研究

目前成岩作用研究主要集中于砂岩及碳酸盐岩,对泥页岩本身成岩作用及阶段划分的研究较少。随着页岩气研究的兴起,泥页岩成岩作用逐渐受到科研工作者的重视,因此,基于泥岩样品的热模拟实验,对不同演化阶段的样品分别进行X衍射分析、镜质体反射率(R_o)测试、岩石热解(T_(max))分析,应用测试及分析结果进行泥页岩黏土矿物演化的定量表征,并划分泥页岩成岩阶段,为泥页岩储层评价提供参考。研究结果表明,随着泥页岩成岩作用的进行,黏土矿物演化主要表现为高岭石向伊利石和伊/蒙(I/S)混层转化,可将泥页岩成岩作用划分为六个阶段,每个阶段对应的R_o、T_(max)临界值大于砂岩成岩作用相应的R_o、T_(max)临界值。

Study on the Evolution of Clay Mineral and the Division of Diagenesis Stages in Mud Shale Based on Thermal Simulation

At present, the diagenesis is mainly focused on sandstone and carbonate rock, and little research has been done on diagenesis and stage division of mud shale. With the development of shale gas research, mud shale diagenesis has attracted the attention of more and more scientific researchers. Therefore, the thermal simulation experiment of the mudstone samples were implemented in the study, and during the experiment, the X-ray diffraction analysis, vitrinite reflectance(RO) measurement and rock pyrolysis (Tmax)analysis accomplished. The quantitative characterization of clay mineral evolution and the division of diagenesis stages were completed based on the above experimental results, and the study mainly provides reference for the reservoir evaluation of mud shale.