陆相页岩岩相非均质性及储层孔隙发育特征:以四川盆地自流井组东岳庙段页岩为例  

Lithofacies heterogeneity and reservoir pore development characteristics of continental shale:A case study of the Dongyuemiao shale of the Ziliujing Formation in the Sichuan Basin

作　　者：舒志国[1] 舒逸 陈绵琨[2] 彭伟[2] 刘皓天[2] 肖雄[2] SHU Zhiguo;SHU Yi;CHEN Miankun;PENG Wei;LIU Haotian;XIAO Xiong(Jianghan Oilfield Branch Company,SINOPEC,Qianjiang Hubei 433124,China;Institute of Petroleum Exploration and Development,Jianghan Oilfield Branch Company,SINOPEC,Wuhan 430223,China)

机构地区：[1]中国石油化工股份有限公司江汉油田分公司,湖北潜江433124 [2]中国石油化工股份有限公司江汉油田分公司勘探开发研究院,武汉430223

出　　处：《地质科技通报》2024年第2期1-15,共15页Bulletin of Geological Science and Technology

基　　金：中国石油化工股份有限公司“十条龙”科研项目“复兴侏罗系陆相页岩油气藏地质评价技术”(P21078-2);中国石油化工股份有限公司科研项目(P23077)。

摘　　要：继四川盆地复兴地区涪页10井取得勘探突破后,侏罗系自流井组东岳庙段页岩油气表现出良好的勘探潜力。东岳庙段页岩发育独特的介壳灰岩夹层、黏土矿物含量高(质量分数最高可达60%),储层孔隙类型多样,纵向上具有很强的非均质性。以兴页X井为例,结合测录井资料、岩心观察、氩离子抛光扫描电镜等技术手段,重点剖析了东岳庙段陆相页岩岩相特征及其孔隙发育特征。建立了“夹层+矿物三端元”的陆相页岩岩相划分原则,将东岳庙段陆相页岩纵向上划分为6种岩相,即:介屑纹夹层型黏土页岩相;介屑纹夹层型混合页岩相;介屑灰岩相;粉砂介屑互层型混合页岩相;粉砂介屑互层型黏土页岩相;介壳韵律型混合页岩相。通过氩离子抛光扫描电镜观察发现,该套陆相页岩具有特殊的有机黏土复合体孔,其中介屑纹夹层型黏土页岩相有机孔类型最为发育,而介屑灰岩相有机孔不发育,主要发育粒内溶孔。压汞-氮气吸附联测结果显示6种岩相页岩的孔径分布无明显差异性。综合分析认为,有机质和黏土矿物在成岩演化过程中的相互作用是东岳庙段陆相页岩孔隙发育的主要因素。[Objective] After the exploration break through of the Well Fuye 10 in the Fuxing area of the Sichuan Basin,shale oil and gas from the Dongyuemiao section of the Jurassic Ziliujing Formation showed good exploration potential.The Dongyuemiao shale is characterized by unique shell limestone interlayers,high clay mineral content(up to 60%),various reservoir pore types,and strong vertical heterogeneity.[Methods] Taking the Well Xingye X as an example,combined with logging data,core observation,argon ion polishing scanning electron microscopy(SPE),and other technical means,the lithofacies characteristics and pore development characteristics of continental shale in the Dongyuemiao section were emphatically analysed.[Results] In this study,the principle of continental shale lithofacies division of "interlayer+mineral three-terminalelements" was established,and the continental shale of the Dongyuemiao section was vertically divided into 6 lithofacies:shell rhythmic mixed shale facies,silt shell interbedded clay shale facies,silt lithic interbedded mixed shale facies,lithic limestone facies,lithic interbedded mixed shale facies,and lithic interbedded clay shale facies.Through argon ion polishing and scanning electron microscopy(SEM),it was found that this set of continental shale mainly develops special complex organic clay pores,of which the lithic interbedded clay shale facies was the most developed type of organic pore,while the lithic limestone facies organic pores were not developed,mainly develop intragranular dissolved pores.The mercury intrusion nitrogen adsorption joint measurement results revealed that there was no significant difference in the pore size distribution of the six lithofacies shales.[Conclusion] Comprehensive analysis revealed that the interaction between organic matter and clay minerals during the diagenetic evolution process was the main factor influencing the pore development of continental shale in the Dongyuemiao section.

关 键 词：陆相页岩 岩相非均质性 有机黏土复合体孔 侏罗系 东岳庙段 四川盆地 

分 类 号：P618.2[天文地球—矿床学]