天然气勘探与开发2025，Vol.48Issue(6)：41-53,13.DOI:10.12055/gaskk.issn.1673-3177.2025.06.004
激光扫描共聚焦显微技术表征页岩油赋存特征
Characterization of shale oil occurrence using laser scanning confocal microscopy:A case study of Da'anzhai Member of Jurassic Ziliujing Formation,Sichuan Basin
摘要
Abstract
To clarify the microscopic occurrence characteristics and their main controlling factors of shale oil in the Da'anzhai Member of the Jurassic Ziliujing Formation in the Sichuan Basin,typical shale samples from the study area were qualitatively and quantitatively characterized using the laser scanning confocal microscopy(LSCM),together with scanning electron microscopy(SEM),nuclear magnetic resonance(NMR),and high-pressure mercury intrusion(HPMI)experiments.The relationship between reservoir spaces and oil-bearing properties of different lithofacies was investigated.The following results are obtained.(i)Shale oil exists across the study area,but significantly varies in occurrence state.Heavy components are mainly scattered in the nano-pores of mudstone matrix,with poor mobility,while light components are primarily enriched in strip form in micron-sized fractures such as shell cracked fractures,edge fractures,dissolution fractures,and lime-mud interlayer fractures,with good mobility.(ii)The pore structure is highly heterogeneous in different lithofacies.With the increase of lime content and the decrease of mud content,the total porosity decreases,but the average pore size increases.The proportion of macropore volume increases from 5.08%to 11.95%,accompanied with the rise in the proportion of light oil.(iii)The layered muddy shell shale exhibits a relatively low total porosity,but has a plane porosity up to 40.42%due to the developed multi-genesis microfracture system,making it the most favorable lithofacies for shale oil enrichment in the area.(iv)Based on types of mcirofractures,four occurrence modes of shale oil are identified,i.e.lamina and lamellation fractures,shell edge fractures,shell cracked fractures,and centimeter-sized limy strip cleavage fractures and interlayer fractures.It is concluded that the microfracture network serves as not only the dominant seepage channel but also the prominent reservoir space for shale oil.Therefore,the shale oil exploration in the Da'anzhai Member and even similar shale-limestone mixed rocks should focus on the intervals with developed microfractures.关键词
四川盆地/侏罗系下统自流井组大安寨段/页岩油/赋存机理/激光扫描共聚焦/微裂缝/岩相/可动性Key words
Sichuan Basin/Da'anzhai Member of Lower Jurassic Ziliujing Formation/Shale oil/Occurrence mechanism/Laser scanning confocal microscopy/Microfracture/Lithofacies/Mobility分类
能源科技引用本文复制引用
周翔,肖正录,张少敏,秦春雨,路俊刚,蒋奇君,杨璞,董虎..激光扫描共聚焦显微技术表征页岩油赋存特征[J].天然气勘探与开发,2025,48(6):41-53,13.基金项目
中国石油—西南石油大学创新联合体科技合作项目"四川盆地湖相页岩油富集机理、分布规律及资源潜力研究"(编号:2020CX050000). （编号:2020CX050000）
