岩矿测试2026，Vol.45Issue(1)：101-115,15.DOI:10.15898/j.ykcs.202506040146
准噶尔盆地西北部风城组页岩油微观赋存特征及甜点预测
Microscopic Occurrence Characteristics and Sweet Spot Prediction of Shale Oil in the Fengcheng Formation,Northwestern Junggar Basin
摘要
Abstract
The Fengcheng Formation(P1f)is the main source rock in the northwestern Junggar Basin and is the key horizon for shale oil exploration and development in the future.Previous studies mainly focused on the sedimentary environment,petrology,reservoir pore structure and physical properties of P1f,but relevant research on the microscopic occurrence characteristics of shale oil is relatively weak.To reveal the oil content and micro-occurrence characteristics of shale oil in different lithofacies of P1f in the northwestern Junggar Basin,81 mud/shale samples from 4 wells to effectively avoid the errors and accidents caused by single experiments through the joint application of field emission scanning electron microscope(FE-SEM),nuclear magnetic resonance(NMR)and stepwise extraction experiments.The occurrence state across six lithofacies of shale oil was systematically characterized in the study area.The experimental results show that the combined application of SEM and NMR methods can be used to effectively identify shale oil occurrence states.Free oil exhibits a linear distribution of T2>2 ms,T1/T2 ≈ 10,mainly residing in pores and microfractures>50 nm.Adsorbed oil shows a zonal distribution of T2<2 ms and T1/T2 ≈ 100,occurring as oil films on clay mineral surfaces and within pyrite aggregates.These findings can be used to provide technical support for distinguishing sweet spot shale oil.The integrated application of the NMR method and three-step light/heavy hydrocarbon extraction,combined with the developmental characteristics of shale oil reservoir types across different lithofacies,clearly indicates that the calcareous mudstone/shale is the most favorable lithofacies of P1f,in the study area,followed by dolomitic mudstone/shale(with the strongest oil capacity)and the dolomitic tuff.Among these,the third member of P1f in the area of Well Hashenxie 1 exhibits high oil content(TOC 1.5%-5.13%,S1 1.2-4.02 mg/g,free oil accounting for 20%-40%),high porosity(porosity 4.2%-6.58%,with developed intragranular pores,intergranular pores and micro-fractures),high brittleness(brittle mineral content 55%-71%,Leeb hardness 450-650,good compressibility)and other characteristics,making it the most favorable target section.The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202506040146.关键词
场发射扫描电子显微镜(FE-SEM)/核磁共振(NMR)/页岩油/赋存特征/游离油/吸附油Key words
field emission scanning electron microscope(FE-SEM)/nuclear magnetic resonance(NMR)/shale oil/occurrence characteristics/free oil/adsorbed oil分类
天文与地球科学引用本文复制引用
王艺霏,高瑞佳,魏陌..准噶尔盆地西北部风城组页岩油微观赋存特征及甜点预测[J].岩矿测试,2026,45(1):101-115,15.基金项目
中国石化集团公司项目"中西部陆相页岩油资源潜力与目标评价"(P20049) （P20049）
