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自生高岭石作为沉积岩中最为常见的自生黏土矿物之一,受到了人们的广泛关注。由于自生高岭石可能对储层物性造成较大的影响,在石油地质学、储层沉积学等领域对其进行研究具有重要意义。在前人研究的基础上结合笔者自己的研究,对自生高岭石的形成环境、形成机制、赋存状态及其对储层物性的影响等问题进行归纳总结,主要有以下几点认识:自生高岭石的形成与酸性流体和大气淡水有着直接的关系,同时酸性流体的产生可能受到多种因素如煤系地层、油气充注的影响;长石类矿物的溶蚀作用是自生高岭石形成的主要物质来源,在该过程中Al3+含量并非处于平衡状态;自生高岭石可能形成于埋藏成岩作用多个阶段,但主要在早成岩作用阶段形成;自生高岭石和储层物性之间的关系受其赋存状态、分布特征以及储层砂岩的成熟度等因素的制约。研究还表明,在某些地区,如鄂尔多斯盆地上古生界盒8段,自生高岭石的形成对储层物性是有利的。
As one of the most common authigenic clay minerals in sedimentary rocks, authigenic kaolinite has received extensive attention. Since authigenic kaolinite may have a great impact on reservoir physical properties, it is of great significance to study it in the fields of petroleum geology and reservoir sedimentology. Based on the previous studies, this paper summarizes the forming environment, formation mechanism, occurrence state of authigenic kaolinite and its influence on reservoir physical properties on the basis of the author’s own research. The main points are as follows: The formation of kaolinite is directly related to acidic fluid and atmospheric freshwater. At the same time, the generation of acidic fluid may be affected by many factors such as coal-bearing strata and hydrocarbon filling. The dissolution of feldspar minerals is the formation of authigenic kaolinite Of the main source of material, Al3 + content in the process is not in equilibrium; authigenic kaolinite may be formed in many stages of burial diagenesis, but mainly formed in the early diagenetic stage; the relationship between authigenic kaolinite and reservoir physical properties Due to its occurrence state, distribution characteristics and reservoir sandstone maturity and other factors. The study also shows that in some areas, such as the Upper Paleozoic, Block 8 in Ordos Basin, the formation of authigenic kaolinite is favorable for reservoir physical properties.