石油实验地质2025，Vol.47Issue(3)：541-551,11.DOI:10.11781/sysydz2025030541
北部湾盆地涠西南凹陷流沙港组页岩油储层微观孔隙结构特征与可动性分析
Microscopic pore structure characteristics and mobility of shale oil reservoirs in Liushagang Formation,Weixinan Sag,Beibu Gulf Basin
摘要
Abstract
Shale oil reservoirs are characterized by tightness and strong heterogeneity,and the microscopic pore structures affect the storage and flow of shale oil in reservoirs.However,conventional single analytical methods often fail to accurately characterize these microscopic pore structures.This study aims to reveal the microscopic pore structure and mobility characteristics of shale oil reservoirs,thereby guiding efficient exploration and development of offshore shale oil.Three types of shale oil reservoirs—matrix-type,laminated-type and interbedded-type—in the Liushagang Formation,Weixinan Sag,Beibu Gulf Basin were selected as the research objects.Integrated analytical and testing methods were employed,including cast thin-sections,scanning electron microscopy,high-pressure mercury intrusion,nitrogen adsorption,and nuclear magnetic resonance,to analyze pore structure parameters,mercury intrusion morphology,and adsorption curve characteristics.The results showed that the matrix-type and laminated-type reservoirs exhibited finer grain sizes and relatively underdeveloped pores,domi-nated by slit-shaped pore morphologies.These reservoirs commonly featured bedding fractures,organic pores,interlayer pores within clay minerals,and intercrystalline pores within pyrite.The interbedded-type reservoirs mainly had ink-bottle-shaped pore morphologies,along with intergranular pores within mineral particles,dissolu-tion pores,and fracture networks,showing good pore size distribution and reservoir connectivity.Analysis of shale oil mobility through fluorescence thin sections and nuclear magnetic resonance revealed that the matrix-type and laminated-type reservoirs exhibited relatively poorer mobility,with movable porosities of 0.72%and 4.62%,respectively,along with lower movable oil content.The interbedded-type reservoir exhibited a movable porosity of 6.37%,with lighter hydrocarbon components,better mobility,and higher movable oil content,making it the most favorable reservoir type for shale oil exploration in the Weixinan Sag.关键词
储层孔隙结构/页岩油可动性/流沙港组/古近系/涠西南凹陷/北部湾盆地Key words
reservoir pore structure/shale oil mobility/Liushagang Formation/Paleogene/Weixinan Sag/Beibu Gulf Basin分类
能源科技引用本文复制引用
游君君,胡德胜,袁珍珠,周刚,江黎..北部湾盆地涠西南凹陷流沙港组页岩油储层微观孔隙结构特征与可动性分析[J].石油实验地质,2025,47(3):541-551,11.基金项目
国家重点研发计划项目"中国东部非生物气富集与成藏机理"(2019YFA0708504)资助. （2019YFA0708504）
