泥页岩有机质孔隙差异特征及影响因素分析——以我国典型海相、陆相、过渡相储层为例  

On the Different Characteristics of Organic Pores in Shale and Their Influencing Factors:Taking typical marine,continental,and transitional facies reservoirs in China as examples

作　　者：谷渊涛 李晓霞 万泉[2] 杨曙光 GU YuanTao;LI XiaoXia;WAN Quan;YANG ShuGuang(School of Resources and Environment,Henan University of Engineering,Zhengzhou 451191,China;State Key Laboratory of Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]河南工程学院资源与环境学院,郑州451191 [2]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵阳550081

出　　处：《沉积学报》2021年第4期794-810,共17页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41802143);矿床地球化学国家重点实验室开放基金(SKLODG-201904)。

摘　　要：泥页岩中有机质孔隙是有机质向烃类转化的产物,也是烃类重要的纳米级赋存空间。以我国不同沉积相泥页岩(鄂尔多斯盆地延长组、四川盆地东南缘龙马溪组和牛蹄塘组、南华北盆地山西组)为研究对象,通过有机地球化学和微区分析等手段对有机质孔隙发育特征及影响因素进行了精细表征和深入探讨。结果表明:TOC与孔隙参数的相关性随热成熟度的增加展现出规律性变化,表明热演化是有机质孔隙发育的主要驱动因素。除热成熟度外,四组样品中有机质孔隙的发育特征受多种因素影响:延长组有机质孔隙处于形成阶段,多数有机质不发育孔隙,孔隙的形成主要受有机质类型和显微组分的影响。龙马溪组有机质孔隙普遍发育,为孔隙发育的高峰阶段,有机—无机相互作用制约着孔隙的结构和形貌特征。牛蹄塘组因排烃作用较为完全而处于孔隙收缩阶段,已有较多有机质孔隙被压实而消失,孔隙形态主要受控于微裂隙和有机质—黏土复合体的发育情况。山西组因过高的热演化程度引起有机质结构塌陷,且保存条件极差,处于孔隙的转化和消失阶段;有机质孔隙的发育情况与有机质类型和内部结构直接相关,并受保存条件的严重影响。相关结论有助于深刻理解页岩油气资源赋存富集机理,促进页岩油气资源的勘探开发。Organic pores in shale are the products of the conversion of organic matter(OM)to hydrocarbons,and the important occurrence spaces of hydrocarbons and their evolution are controlled by various factors.In this study,four typical formations of shale reservoirs in China(Yanchang Formation(T3y)in the Ordos Basin,Longmaxi(S1l)and Niutitang Formations(Є1n)in the southeastern Sichuan Basin,and Shanxi Formation(P_(1)s)in the southern North China basin)were selected to analyze the development characteristics of organic pores and influencing factors by using organic geochemical analysis,X-ray diffraction(XRD),low pressure nitrogen adsorption,and field emission scanning electron microscope(FE-SEM).The results showed that the development of organic pores in the four groups of shale samples was significantly different,and the correlation between total organic carbon(TOC)and pore parameters presented regular changes with increasing thermal maturity,indicating thermal evolution drives the formation and evolution of organic pores in shale.Except for thermal maturity,the development of organic pores are affected by multiple factors,and obvious differences are found for the influencing factors of pore characteristics at different evolution stages.For T3y samples(low maturity),organic pores are in the formation stage,and almost no pores are imaged in OM.The formation of organic pores is mainly affected by the type of OM and macerals.The organic pores in S1l samples(high-over maturity)are generally developed,which is the peak stage of pore development.The organic-inorganic interaction restricts the structure and morphological characteristics of the organic pores.Due to the more complete hydrocarbon expulsion,Є1n samples(high-over maturity)are in the shrinkage stage of organic pores,and quantities of organic pores have been compacted and disappeared.At this stage,pore morphology is mainly controlled by microfractures and the development of organic-clay composites.The OM in P_(1)s samples experience structure collapse because of the

关 键 词：影响因素 有机质孔隙 沉积相 泥页岩 热成熟度 

分 类 号：P618.13[天文地球—矿床学]