摘要
以松辽盆地古龙凹陷GY8HC井白垩系青山口组古龙页岩油为例,运用高精度火山灰锆石U-Pb年龄和AstroBayes方法进行沉积速率估算,通过高分辨率的总有机碳含量(TOC)、游离烃含量(S_(1))、热解烃含量(S_(2))以及矿物含量的频谱分析,对过成熟区页岩油的富集特征和主控因素进行研究。结果表明:(1)与页岩油富集相关的TOC、S_(1)、S_(2)都具有显著的斜率振幅调制周期(173×10^(3) a);(2)与岩石矿物组成有关的石英和伊蒙混层含量则具有显著的长偏心率周期(405×10^(3) a);(3)与高成熟区GY3HC井和中成熟区ZY1井的对比研究表明,过成熟区青山口组页岩油原位富集特征明显,且与TOC具有显著正相关性,说明高TOC是过成熟区页岩油富集的关键要素;(4)173×10^(3)a周期对应的12~13 m沉积厚度可作为研究区页岩油开发的箱体高度,处于青山口组页岩压裂所生成的最优缝高范围(10~15 m)。轨道强迫的气候变化不仅控制松辽盆地有机碳埋藏和岩性组成的沉积韵律,也影响现今古龙页岩油的富集特征和甜点层系。
Taking the GY8HC well in the Gulong Sag of the Songliao Basin as an example,this study utilized high-precision zircon U-Pb ages from volcanic ashes and AstroBayes method to estimate sedimentation rates.Through spectral analysis of high-resolution total organic carbon content(TOC),laboratory-measured free hydrocarbons(S_(1)),hydrocarbons formed during pyrolysis(S_(2)),and mineral contents,the enrichment characteristics and controlling factors of shale oil in an overmature area were investigated.The results indicate that:(1)TOC,S_(1),and S_(2) associated with shale oil enrichment exhibit a significant 173×10^(3) a obliquity amplitude modulation cycle;(2)Quartz and illite/smectite mixed-layer contents related to lithological composition show a significant 405×10^(3) a long eccentricity cycle;(3)Comparative studies with the high-maturity GY3HC well and moderate-maturity ZY1 well reveal distinct in-situ enrichment characteristics of shale oil in the overmature Qingshankou Formation,with a significant positive correlation to TOC,indicating that high TOC is a key factor for shale oil enrichment in overmature areas;(4)The sedimentary thickness of 12–13 m corresponding to the 173×10^(3)a cycle can serve as the sweet spot interval height for shale oil development in the study area,falling within the optimal fracture height range(10–15 m)generated during hydraulic fracturing of the Qingshankou shale.Orbitally forced climate changes not only controlled the sedimentary rhythms of organic carbon burial and lithological composition in the Songliao Basin but also influenced the enrichment characteristics and sweet spot distribution of Gulong shale oil.
作者
王华建
刘真吾
李山
柳宇柯
高爽
吕亦然
吴怀春
张水昌
WANG Huajian;LIU Zhenwu;LI Shan;LIU Yuke;GAO Shuang;LYU Yiran;WU Huaichun;ZHANG Shuichang(Key Laboratory of Deep Petroleum Intelligent Exploration and Development,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Key Laboratory of Petroleum Geochemistry,China National Petroleum Corporation,Beijing 100083,China;State Key Laboratory of Continental Shale Oil,Daqing 163712,China;School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 100083,China;College of Geoscience and Surveying Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China)
出处
《石油勘探与开发》
北大核心
2025年第5期1080-1091,共12页
Petroleum Exploration and Development
基金
国家自然科学基金(42372162,4244205C)
黑龙江省揭榜挂帅项目(2022-JS-1740,2022-JS-1853)
中国科学院抢占科技制高点专项项目(THEMSIE04010103)。
关键词
地球轨道
气候变化
有机质富集
松辽盆地
白垩系
青山口组
古龙页岩油
Earth orbits
climate change
organic matter enrichment
Songliao Basin
Creataceous
Qingshankou Formation
Gulong shale oil
