石油学报 ›› 2022, Vol. 43 ›› Issue (10): 1395-1408.DOI: 10.7623/syxb202210004

• 地质勘探 • 上一篇    下一篇

鄂尔多斯盆地南部延长组7段页岩孔隙特征及页岩油赋存方式

白莹, 白斌, 徐旺林, 张月巧, 孙远实, 刘羽汐, 高建荣, 王夏阳   

  1. 中国石油勘探开发研究院 北京 100083
  • 收稿日期:2021-09-09 修回日期:2022-05-27 出版日期:2022-10-25 发布日期:2022-11-05
  • 通讯作者: 徐旺林,男,1970年6月生,2006年获中国石油大学(北京)博士学位,现为中国石油勘探开发研究院高级工程师,主要从事综合地质研究及地震解释工作。Email:wlxu@petrochina.com.cn
  • 作者简介:白莹,女,1990年2月生,2017年获北京大学博士学位,现为中国石油勘探开发研究院工程师,主要从事沉积储层研究。Email:byshimmer@petrochina.com.cn
  • 基金资助:
    中国石油天然气股份有限公司科学研究与技术开发项目(2021-DJ2203,2021-DJ1806和2021DJ0404)、国家自然科学基金项目(No.42072186)和中国石油天然气股份有限公司油气和新能源分公司项目(kt2020-06-02,2022KT-03-02)资助。

Pore characteristics of shale and occurrence mode of shale oil in Member 7 of Yanchang Formation in southern Ordos Basin

Bai Ying, Bai Bin, Xu Wanglin, Zhang Yueqiao, Sun Yuanshi, Liu Yuxi, Gao Jianrong, Wang Xiayang   

  1. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
  • Received:2021-09-09 Revised:2022-05-27 Online:2022-10-25 Published:2022-11-05

摘要: 鄂尔多斯盆地三叠系延长组7段(长7段)页岩油勘探潜力巨大,开展页岩储层特征研究对于明确优势储层、指导下一步页岩油勘探部署具有重要意义。基于露头及岩心观察、岩石薄片鉴定、地球化学特征和孔隙度、渗透率等测试资料,系统分析了鄂尔多斯盆地南部长7段页岩的孔隙特征,并探讨了长7段页岩油的赋存方式。盆地南部地区长7段发育隐纹层型、粒序纹层型、波状纹层型、平直纹层型和断续纹层型5类页岩,储集空间类型包括有机储集空间、无机孔隙和裂缝。平直纹层型页岩是最好的页岩油储集岩性,主要发育超压破裂缝、有机质孔和弯曲—平直狭长缝状粒间孔等储集空间,以平行板状宏孔和中孔为主。页岩油储层中孔和宏孔的复杂程度会影响孔隙结构分形维数D1和孔隙表面分形维数D2的相对关系,而大量发育的微孔可能会提高孔隙结构的复杂性。结合页岩类型和孔隙特征,认为长7段页岩油具有"自生自储"、"近源聚集"和"短距离聚集"3类富集模式特征,受控于连续沉积的页岩岩相沉积序列,表现为连续成藏—富集。

关键词: 鄂尔多斯盆地, 延长组7段, 页岩油, 孔隙特征, 赋存方式

Abstract: There is great exploration potential for shale oil in Member 7 (Chang 7) of the Triassic Yanchang Formation in Ordos Basin. The study of shale reservoir characteristics is of great significance to identify the favorable reservoirs and guide the further exploration of shale oil. Based on the test data such as outcrop and core observation, rock thin sections identification, geochemical characteristics, porosity, and permeability, the pore characteristics of shale in Chang 7 in southern Ordos Basin were systematically analyzed, and the occurrence mode of shale oil in Chang 7 was also explored. Five types of shale, i.e., cryptalgalaminite type, graded bedding type, wavy lamina type, horizontal lamina type and intermittent lamina type, are developed in Chang 7 in the southern part of the basin. The types of reservoir space include organic reservoir space, inorganic pore and fracture. The horizontal lamina type is the best shale oil reservoir, where reservoir spaces such as overpressure fracture, organic matter pore, curved-straight long and narrow crack-like intergranular pore are well developed, dominated by parallel tabular macropores and mesopores. The complexity of mesopores and macropores in shale oil reservoirs will affect the relative relationship between the fractal dimension D1 and D2 of pore surface, and a large number of micropores may increase the complexity of pore structure. Based on shale types and pore characteristics, it is considered that the shale oil in Chang 7 is characterized by "self-generation and self-accumulation", "short-distance enrichment" and "long-distance enrichment", controlled by the continuously deposited sedimentary sequence of shale facies, and presented as continuous accumulation and enrichment.

Key words: Ordos Basin, Member 7 of Yanchang Formation, shale oil, pore characteristics, occurrence mode

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