黏土沉积微结构特征及其沉积环境  

Microstructure Characteristics and Sedimentary Environments of Clay Sediments

作　　者：吴冬 邓虎成 解馨慧[3] 刘慧 曹凯旋[2] WU Dong;DENG HuCheng;XIE XinHui;LIU Hui;CAO KaiXuan(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;College of Energy(College of Modern Shale Gas Industry),Chengdu University of Technology,Chengdu 610059,China;College of Geophysics,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室,成都610059 [2]成都理工大学能源学院(页岩气现代产业学院),成都610059 [3]成都理工大学地球物理学院,成都610059

出　　处：《沉积学报》2025年第2期376-386,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42072182);中石化西南油气分公司项目(KJ-766-2330)。

摘　　要：【目的】作为非常规油气资源的重要组成,页岩油气资源的基础研究逐渐受到重视。黏土沉积微结构对页岩页理、纹层结构产生影响,进而影响页岩储层储集能力和开发效果,明确黏土沉积微结构有利于页岩油气的分布预测及开发。【方法】黏土颗粒除受物理作用影响,还发生化学吸附和絮凝,形成絮凝程度不一的絮凝物。絮凝物的基本单元是板状颗粒或域,进一步形成絮或链,最终在电荷作用下形成纸牌屋结构。在沉积阶段,影响絮凝程度的物理—化学因素繁多,对黏土沉积微结构开展物理—化学影响因素研究,并结合泥岩颗粒集合体其他组构的分析,可以对泥页岩沉积环境进行识别和描述。【结果】目前,该项研究尚显不足:(1)尚未建立完善的沉积地质模型;(2)包括絮凝物在内的泥岩颗粒集合体组构的定量研究不足,尚未成熟地使用人工智能图像识别技术;(3)我国西部海相黑色页岩沉积微环境及其内部集合体特征研究有待深化;(4)研究技术方法略显单一。【结论】对黏土沉积微结构进行定性和定量描述,并开展泥岩颗粒集合体形成环境解释,能实现复杂多变的沉积微环境精细刻画,深化对湖泊、海洋等泥页岩沉积环境分异特征的认识,进而揭示高精度范围内页岩储层品质的差异,为页岩地质和工程“甜点”的选取和开发奠定基础。[Objective]As an important component of unconventional oil and gas resources,the basic research of shale oil and gas resources has gradually gained momentum.With the continuous microscopization of the study scale,it is increasingly important to study the microstructures of clay sediments.Microstructures of clay sediments have an impact on shale foliation and lamination structure,thus influencing the shale reservoir capacity and development effect.Therefore,further understanding of clay sediments microstructures is conducive to the distribution prediction and exploitation of shale oil and gas resources[.Methods]In addition to being affected to rows and columns by physical action,clay particles also undergo chemical adsorption and flocculation to form floccules with varying degrees.The basic floccule unit is tabular particles or domains,further forming flocs or chains,before finally forming a card house structure under the electric charge.There are many types of structures,reflecting the difference of flocculation.In the sedimentary stage,the physical and chemical factors affecting the flocculation include particle size,particle content,external hydrodynamic strength and flow properties,climate,electrolyte concentration,ion type,pH value,and organic matter.By studying the physical and chemical factors affecting the microstructures of clay sediments and analyzing the other components of mudstone composite particles such as volcanic rock fragments,shale lithics,muddy intraclasts,and fecal pellets,the sedimentary environments of mudstone and shale can be identified and described[.Results]Flocculation enables clay minerals to be deposited in high-energy hydrodynamic environment.The larger the clay particle size is,the less likely it is to flocculate.Moreover,relatively turbulent water interferes with flocculation and prevents mudstone particles from forming layers.Climatic stratification and storm pressure conduction affect the microstructure of clay deposits.Strong acidic water is conducive to the flocculation of clay

关 键 词：泥页岩 沉积微结构 絮凝 物理化学因素 沉积微环境 

分 类 号：P512.2[天文地球—地质学]