碎屑岩自生粘土矿物的沉淀作用及其对储层的影响——以川西坳陷上三叠统须家河组砂岩为例

Precipitation Interaction of Authigenic Clay Minerals for Clastic Reservoirs and its Effect on Reservoirs: a Case Study of Sandstones of Xujiahe Formation of Upper Triassic from Western Sichuan Depression

粘土矿物是影响碎屑岩储层物性的重要因素。本文以川西坳陷孝泉-新场-合兴场地区上三叠统须家河组砂岩为例,应用铸体薄片、普通薄片、X射线衍射分析和扫描电镜分析,研究了在成岩过程中自生粘土矿物的沉淀作用及其对储层的影响。结果表明自生绿泥石对储层原生孔隙的保存和次生孔隙的发育有利,自生高岭石的含量反映了次生孔隙的发育程度,而伊利石对储层的影响是负面的。

It is well known that clay minerals are the important factor that controls elastic reservoir properties. This paper takes upper Triassic Xujiahe formation sandstones in western Sichuan depression as an example to analyze diagenesis of authigenic clay minerals for clastic reservoirs and its effect on reservoirs by means of techniques of core cast slice, ordinary slice, X - diffraction and micro - observation of scanning electric microscope. The results showed that authigenic chlorite was favour of protection of primary porosity and development of secondary porosity, percentage of authigenic kaolinite was positively associated with the development of secondary porosity, while illite was negatively influence on sandstone reservoirs.