石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (6): 1947-1959.doi: 10.11743/ogg20250613

• 油气地质 • 上一篇    下一篇

苏北盆地古近系泰州组二段页岩油储层差异成储机理

高玉巧1,2,3(), 蔡潇1,3(), 夏威1,3, 马晓东1,2,3, 昝灵1,2, 花彩霞1,2, 李辉1,3, 朱一川1,3, 王雨梦1,3   

  1. 1.页岩油气富集机理与高效开发全国重点实验室,北京 100083
    2.中国石油化工股份有限公司 华东油气分公司 勘探开发 研究院,江苏 南京 210000
    3.中国石化深层煤层气勘探开发重点实验室,江苏 南京 210000
  • 收稿日期:2025-07-30 修回日期:2025-11-17 出版日期:2025-12-30 发布日期:2025-12-25
  • 通讯作者: 蔡潇 E-mail:gaoyq.hdsj@sinopec.com;caix.hdsj@sinopec.com
  • 第一作者简介:高玉巧(1978—),女,博士、研究员,非常规油气地质研究与勘探开发管理。E-mail:gaoyq.hdsj@sinopec.com
  • 基金项目:
    国家自然科学基金(U24B6002);中国石化科技部项目(P24117);中国石化科技部项目(P23190)

Differential formation mechanisms of shale oil reservoirs in the 2nd member of the Paleogene Taizhou Formation, Subei Basin

Yuqiao GAO1,2,3(), Xiao CAI1,3(), Wei XIA1,3, Xiaodong MA1,2,3, Ling ZAN1,2, Caixia HUA1,2, Hui LI1,3, Yichuan ZHU1,3, Yumeng WANG1,3   

  1. 1.State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 100083,China
    2.Exploration and Development Research Institute,East China Oil & Gas Company,SINOPEC,Nanjing,Jiangsu 210000,China
    3.Key Laboratory of Deep Coalbed Methane Exploration and Production,SINOPEC,Nanjing,Jiangsu 210000,China
  • Received:2025-07-30 Revised:2025-11-17 Online:2025-12-30 Published:2025-12-25
  • Contact: Xiao CAI E-mail:gaoyq.hdsj@sinopec.com;caix.hdsj@sinopec.com

摘要:

为研究苏北盆地古近系泰州组二段页岩油储层的岩相组构、储集类型、含油性和可动性,基于取心井HY2井页岩样品,开展了大面积薄片拼接成像分析、氩离子抛光-场发射扫描电镜(FE-SEM)观察、全岩X射线衍射(XRD)分析、总有机碳含量(TOC)测定、岩石物性分析和激光共聚焦显微镜(CLSM)观测等实验,系统研究了泰州组二段页岩储层发育特征和差异成储机理。研究结果表明:①页岩储层矿物组成以高碳酸盐矿物、高黏土矿物和低长英质矿物含量为特征。碳酸盐矿物主要以泥晶分散状、团块状和纹层状形式产出。②页岩纹层发育程度较低且类型较单一,主要发育碳酸盐纹层和生物碎屑纹层,少见长英质纹层,页岩纹层矿物组合以“碳酸盐矿物+黏土矿物”和“生物碎屑+黏土矿物”两种类型为主。③页岩主要发育块状灰质泥岩和纹层状含灰/灰质页岩两种岩相。储集空间以黏土矿物晶间孔为主导,纹层缝和高角度裂缝发育少,局部可见少量溶蚀孔、粒间孔和有机质孔。④页岩油主要以分散状赋存,轻/重比介于0.52 ~ 0.77。⑤沉积环境控制页岩储层岩相组合,成岩作用控制页岩储层孔隙演化,构造作用控制页岩储层裂缝系统,页岩生烃热演化史控制页岩油气分布。

关键词: 纹层, 岩相, 差异化成储, 储集空间, 页岩油, 泰州组二段, 古近系, 苏北盆地

Abstract:

This study aims to examine the lithofacies fabrics, reservoir types, oil-bearing properties, and crude oil mobility of shale oil reservoirs in the 2nd member of the Paleogene Taizhou Formation (also referred to as the Tai 2 Member) in the Subei Basin. To this end, a series of experiments are conducted on shale samples from cored well HY2, including analysis of large-area thin-section mosaic imaging, argon ion milling-field emission scanning electron microscopy (FE-SEM), and whole-rock X-ray diffraction (XRD), together with total organic carbon (TOC) content determination, petrophysical property analysis, and confocal laser scanning microscopy (CLSM) observation. Building on these, we systematically examine the developmental characteristics and differential formation mechanisms of shale reservoirs in the Tai 2 Member. The results indicate that the shale reservoirs are characterized by mineral composition of high carbonate and clay mineral content and low felsic mineral content. The carbonate minerals primarily occur as dispersed micrite, lumps in matrix, and laminae. The shale laminae exhibit a low degree of development and simple types. They are dominated by carbonate and bioclastic laminae, with a minor presence of felsic laminae. Primary mineral assemblages of the shale laminae include “carbonate minerals with clay minerals” and “bioclasts with clay minerals.” The shales consist predominantly of two lithofacies types: massive calcareous mudstones and lamellar argillaceous/ calcareous shales. The reservoir spaces are dominated by intercrystalline pores within clay minerals, with rare lamina-parallel fractures and high-angle fractures. In addition, small quantities of dissolution pores, intergranular pores, and organic pores are locally visible. Shale oil is mainly dispersed, with a light-to-heavy component ratio ranging from 0.52 to 0.77. In shale reservoirs in the Tai 2 Member, lithofacies assemblages are governed by the sedimentary environment, pore evolution is controlled by diagenetic processes, and fracture systems are determined by tectonism. Additionally, the distribution of shale oil in these reservoirs is governed by the hydrocarbon generation and thermal evolution histories of shales.

Key words: laminae, lithofacies, differential reservoir formation, reservoir space, shale oil, 2nd member of the Taizhou Formation (Tai 2 Member), Paleogene, Subei Basin

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