石油与天然气地质 ›› 2020, Vol. 41 ›› Issue (4): 719-729.doi: 10.11743/ogg20200406

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地延长组长7段页岩油形成富集机理

李士祥1,2(), 牛小兵2,3,4, 柳广弟5,6, 李继宏1,2, 孙明亮5,6, 游富粮5,6, 何昊楠7   

  1. 1. 中国石油 长庆油田分公司 勘探开发研究院, 陕西 西安 710018
    2. 低渗透油气田勘探开发国家工程实验室, 陕西 西安 710018
    3. 中国石油 长庆油田分公司 第八采油厂, 陕西 西安 710000
    4. 中国石油大学(华东), 山东 青岛 266580
    5. 中国石油大学(北京) 地球科学学院, 北京 102249
    6. 油气资源与探测国家重点实验室, 北京 102249
    7. 中国石油大学(北京) 克拉玛依校区, 新疆 克拉玛依 834000
  • 收稿日期:2019-11-19 出版日期:2020-08-01 发布日期:2020-08-11
  • 作者简介:李士祥(1981-),男,博士、高级工程师,沉积学及石油地质。E-mail:sxlee1981_cq@petrochina.com.cn
  • 基金资助:
    国家科技重大专项(2016ZX05050);国家科技重大专项(2017ZX05001002);国家重点基础研究发展计划(973计划)项目(2014CB239003)

Formation and accumulation mechanism of shale oil in the 7th member of Yanchang Formation, Ordos Basin

Shixiang Li1,2(), Xiaobing Niu2,3,4, Guangdi Liu5,6, Jihong Li1,2, Mingliang Sun5,6, Fuliang You5,6, Haonan He7   

  1. 1. Exploration and Development Research Institute of Changqing Oilfield Company, PetroChina, Xi'an, Shaanxi 710018, China
    2. National Engineering Laboratory for Exploration and Development of Low-Permeability Oil&Gas Fields, Xi'an, Shaanxi 710018, China
    3. No.8 Oil Production Plant of Changqing Oilfield Company, PetroChina., Xi'an, Shaanxi 710000, China
    4. China University of Petroleum(East China), Qingdao, Shandong 266580, China
    5. College of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China
    6. State Key Laboratory of Petroleum Resource and Prospecting, Beijing 102249, China
    7. China University of Petroleum(Beijing) at Karamay, Karamay, Xinjiang 834000, China
  • Received:2019-11-19 Online:2020-08-01 Published:2020-08-11

摘要:

页岩油是亟待开发利用的一种非常规油气资源。利用岩石地球化学和烃源岩地球化学的方法对鄂尔多斯盆地延长组长7段页岩油形成的基本条件和富集机制进行了系统分析。长7段沉积了平均残余有机碳丰度达7.4%的特高丰度富有机质泥页岩,该套泥页岩中发育丰富的微纳米孔隙,为页岩油的富集创造了良好的条件。长7段页岩油富集的主要机制包括:①高有机物生产力和强还原水体令长7段沉积期的超富营养化湖盆中的有机质得以有效保存,形成高有机质丰度的泥页岩,为页岩油形成提供了物质基础;②长7段富有机质泥页岩生油能力强、转化效率高、排油强度大,为页岩油的规模形成提供了良好条件;③有机质吸附与孔隙容留双机制的页岩油赋存方式,为页岩油的富集提供了多种方式。

关键词: 富有机质页岩, 富集机理, 页岩油, 延长组长7段, 鄂尔多斯盆地

Abstract:

Shale oil is a kind of important unconventional hydrocarbon resource in urgent need of exploitation.A systematic analysis of the forming conditions and accumulation mechanisms of shale oil in the 7th member of the Yanchang Formation (Chang 7 member) in Ordos Basin was carried out by using petro-chemistry and source rock geochemistry methods.The results show that the oil shale deposited in the member is extremely rich in organic matter with an average residual organic carbon abundance of 7.4%, and contains well-developed micro- and nano-pores for shale oil accumulation.Three main mechanisms of shale oil accumulation in the member are brought forward in this study:(1) both high organic matter productivity and strong reducing water environment served to effectively preserve organic matters in the super eutrophic lake basin during deposition, and organic shale of high abundance developed thereby provided the material basis for shale oil generation; (2) organic-rich shale characterized by strong oil-generating capacity, high conversion efficiency, and high intensity of oil expulsion in the member provided favorable conditions for the generation of shale oil in large scale; and (3) the dual occurrence mode of shale oil, i.e., organic matter adsorption and pore retention, provided various ways for the enrichment of shale oil in the member.

Key words: organic-rich shale, accumulation mechanism, shale oil, Change 7 member, Ordos Basin

中图分类号: