石油实验地质2026，Vol.48Issue(1)：74-88,15.DOI:10.11781/sysydz2026010074
陆相湖盆不同岩相页岩储层特征及孔缝发育差异性机理
Reservoir characteristics and differential development mechanisms of pores and fractures in shales with different lithofacies of continental lacustrine basins:
摘要
Abstract
A large set of thick lacustrine organic-rich shale is developed in the second member of Paleojene Funing Formation(Fu-2 member)in Gaoyou Sag,Subei Basin.It is of great theoretical significance for shale oil explo-ration to clarify the differential development mechanisms of shale reservoir structures in different organic-rich lithofacies.Large-area scanning electron microscopy(MAPS)analysis,CT scanning,and focused ion beam scanning electron microscopy(FIB-SEM)were used to analyze the pore and fracture structure characteristics of shales with different lithofacies of Fu-2 member in the Subei Basin.It was found that the Fu-2 member in Subei Basin mainly developed three types of high-quality shales:calcareous dolomitic shale,felsic-calcareous dolomitic shale,and felsic-argillaceous shale,with significant differences in mineral composition and sedimentary struc-ture.Overall,the types of pores and fractures could be divided into organic pores and fractures,intergranular pores,dissolution pores(carbonate minerals and K-feldspar),and inorganic fractures.The results showed that mineral compositions and structural characteristics were the main controlling factors affecting the development of pore and fracture structures in the three high-quality shale lithofacies of Fu-2 member in Subei Basin.Carbonate mineral dissolution pores and inorganic fractures accounted for the highest proportions in calcareous dolomitic shale.Felsic intergranular pores and inorganic fractures had the highest proportions in felsic-calcareous dolomitic shale.Felsic intergranular pores and clay mineral inorganic fractures had the highest proportions in felsic-argillaceous shale.Influenced by diagenesis,the dissolution pore size and pore-forming efficiency of carbonate minerals(calcite and dolomite)in calcareous dolomitic shale were higher than those in felsic-argillaceous shale.In addition,the main lamina types developed in the laminated shale of the study area included felsic lamina,carbonate mineral lamina,and argillaceous lamina,with surface porosity decreasing successively in this order.The laminated shale promotes the development of a large number of horizontal laminae fractures,providing more favorable channels for the migration of organic acids,resulting in higher dissolution pore size and pore-forming efficiency compared to laminated or massive shale.关键词
湖相页岩/孔隙结构/微裂缝/发育机理/阜二段/高邮凹陷/苏北盆地Key words
lacustrine shale/pore structures/microfractures/development mechanism/second member of Funing Formation/Gaoyou Sag/Subei Basin分类
能源科技引用本文复制引用
刘启东,李鹤永,段宏亮,杨艳,孙雅雄,杨保良,付茜,邢玉洁,宋丽艳..陆相湖盆不同岩相页岩储层特征及孔缝发育差异性机理[J].石油实验地质,2026,48(1):74-88,15.基金项目
中国石化科技部项目"东部断陷盆地页岩储层差异演化机制及建模"(P24207)、"东部富油气凹陷及周缘资源评价"(P23234)和江苏油田科技项目"江苏油田探区'十四五'油气资源评价"(JS24001)联合资助. （P24207）
