石油与天然气地质 ›› 2023, Vol. 44 ›› Issue (4): 946-961.doi: 10.11743/ogg20230412

• 油气地质 • 上一篇    下一篇

细粒沉积岩典型低阻油层成因及甜点分布

印森林1(), 陈旭2, 杨毅3, 章彤4, 程皇辉4, 姜涛4, 熊亭5, 刘娟霞3, 何理鹏5, 杨小江5   

  1. 1.长江大学 录井技术与工程研究院,湖北 荆州 430023
    2.长江大学 地球科学学院,湖北 武汉 430100
    3.中法渤海地质服务有限公司,天津 300452
    4.中国石油 新疆油田分公司,新疆 克拉玛依 834000
    5.中海石油(中国)有限公司 深圳分公司,广东 深圳 518067
  • 收稿日期:2023-02-02 修回日期:2023-05-20 出版日期:2023-08-01 发布日期:2023-08-09
  • 第一作者简介:印森林(1983—), 男, 副教授、博士生导师, 油气田开发地质。E-mail:yinxiang_love@qq.com
  • 基金项目:
    长江大学地质资源与地质工程一流学科开放基金项目(2019KFJJ0818022);油气藏地质与工程国家重点实验室开放基金项目(PLN2022_19)

Origin and sweet spots of typical low-resistivity oil reservoirs of fine-grained sedimentary rocks

Senlin YIN1(), Xu CHEN2, Yi YANG3, Tong ZHANG4, Huanghui CHENG4, Tao JIANG4, Ting XIONG5, Juanxia LIU3, Lipeng HE5, Xiaojiang YANG5   

  1. 1.Institute of Mud Logging Technology and Engineering,Yangtze University,Jingzhou,Hubei 430023,China
    2.School of Geosciences,Yangtze University,Wuhan,Hubei 430100,China
    3.China-France Bohai Geoservices Co. Ltd. ,CNOOC,Tianjin 300452,China
    4.Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China
    5.Shenzhen Branch of CNOOC,Shenzhen,Guangdong 518067,China
  • Received:2023-02-02 Revised:2023-05-20 Online:2023-08-01 Published:2023-08-09

摘要:

细粒沉积岩已成为非常规油气勘探的重要目标,普遍发育了低电阻率油气层。利用测井、录井、地震和薄片电镜测试等资料,结合相控储层参数分布技术,揭示了细粒沉积岩典型低阻油层成因机制,并提出了3类基于低阻成因的甜点分布规律。研究表明:①低阻油层成因主要包括大比表面积、高含量伊/蒙混层矿物、发达的微孔隙网络及其内部束缚水、高矿化度水以及高含量导电矿物等5个方面。②识别出了3类细粒沉积岩低阻类型,包括高泥质含量致密型低阻油层(致密低阻型)、高含量导电矿物型低阻油层(导电矿物低阻型)和疏松砂岩强连通水网型低阻油层(强连通水网导电低阻型),并在此基础上进行了成因分析。③明确了低阻隐蔽油层的甜点分布特征。致密型低阻油层甜点主要发育在电阻率相对较高的储层中,导电矿物型低阻油层甜点主要发育在白云质粉砂岩基质溶蚀段与白云质泥/页岩裂缝发育段,而强连通水网导电型低阻油层甜点主要发育在具有双模态孔隙结构的极细粒岩性中。研究结果对于指导下一步细粒沉积岩储层油气勘探意义重大。

关键词: 油气甜点, 导电矿物, 页岩, 致密储层, 细粒沉积岩, 低阻油层, 非常规油气勘探

Abstract:

Fine-grained sedimentary rocks, in which low-resistivity oil and gas reservoirs are well developed, have become a significant target in unconventional hydrocarbon exploration. The study serves to reveal the genetic mechanism of typical low-resistivity oil reservoirs of fine-grained sedimentary rocks in applying the data from logging, seismic and thin-section electron microscopy (EM), as well as well facies-controlled reservoir parameter distribution, while proposing three sweet-spot distribution patterns under low resistivity. The research results are shown as follows. First, the origin of low-resistivity reservoirs mainly includes the large specific surface area, high content of mixed layer illites/smectites, well-developed micropore network and high bound water content, high-salinity water and high content of conductive minerals. Second, we propose three typical types of fine-grained sedimentary rocks with low resistivity, including tight low-resistivity oil reservoir with high mud content (i.e., tight reservoir of low resistivity), low-resistivity oil reservoir with high content of conductive minerals (i.e., conducive mineral-dominant reservoir of low resistivity) and water network low-resistivity oil reservoir with well-connected loose sandstones (i.e., well-connected water network conductive reservoir of low resistivity). Meanwhile, their genetic mechanisms are analyzed built on this. Third, the sweet-spot distribution patterns in subtle low-resistivity reservoirs are clarified. The tight reservoir of low resistivity has the sweet spots mainly developed in those of relatively higher resistivity; the conductive mineral-dominant type has the sweet spots mainly grown in the dissolved section of the dolomitic siltstone matrix and the section with well-developed dolomitic mud/shale fractures; meanwhile, the well-connected water network conductive reservoir of low resistivity has the sweet spots mainly developed in the ultra-fine-grained rocks with dual-mode pore structure. The results are of great significance to guiding the exploration of fine-grained sedimentary oil/gas reservoirs.

Key words: hydrocarbon sweet spot, conductive mineral, shale, tight reservoir, fine-grained sedimentary rock, low-resistivity oil reservoir, unconventional oil/gas exploration

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