黄骅坳陷上古生界储层粘土矿物研究

通过对黄骅坳陷上古生界储层78个样品的X衍射分析、扫描电镜和铸体薄片观察指明其储层中粘土矿物以伊利石、伊/蒙间层为主,含少量自生高岭石及绿泥石,产状以薄膜式、搭桥式为主。随深度增加伊利石含量上升、伊/蒙间层比增大,致使储层孔、渗减小。与压汞测试结果进行对比后确定粘土矿物与压汞曲线间存在三种典型对照关系。同时,粘土矿物组合暗示本区为干旱盐湖的古环境。全区成岩环境均为碱性,仅在油藏附近表现为碱-酸-碱的变化过程。

Study on clay minerals in Paleozoic reservoirs in the Huanghua Depression

X-ray diffraction,scanning electron microscopy and casting thin observation of 78 samples from Paleozoic reservoirs in the Huanghua Depression indicate that the main clay mineral are mainly as follow illite,illite-smectite and there are a few authigenic kaolinite and chlorite and the clay mineral appear as film-like style and bridge type.Illite content and I/S increase with depth increasing,which lead to the decrease of permeability of reservoir pore.Three typical of the relationship between the mercury curves and clay minerals were obtained by taking pressured-mercury testing.The clay mineral assemblages imply that this area＇s ancient environment was dry-salt lake;the regional diagenetic environment were alkaline;the environment being close to oil reservoir showed individually alkali-acid-alkali process.