油气藏评价与开发 ›› 2025, Vol. 15 ›› Issue (5): 844-857.doi: 10.13809/j.cnki.cn32-1825/te.2025.05.014

• 工程工艺 • 上一篇    下一篇

夹层型页岩油储层自吸排油特征及其主控因素研究

樊云鹏1,2(), 文志刚1,2, 李桢3, 何右安3, 田伟超1,2(), 刘雨航1,2   

  1. 1.油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院),湖北 武汉 430100
    2.油气资源与勘探技术教育部重点实验室(长江大学),湖北 武汉 430100
    3.中国石油长庆油田分公司勘探开发研究院,陕西 西安 710018
  • 收稿日期:2025-02-08 发布日期:2025-09-19 出版日期:2025-10-26
  • 通讯作者: 田伟超(1990—),男,博士,副教授,主要从事油气地球化学与石油地质学方向的研究。地址:湖北省武汉市蔡甸区大学路111号,邮政编码:430100。E-mail:648493030@qq.com
  • 作者简介:樊云鹏(1995—),男,在读博士研究生,主要从事非常规油气地质方向的研究。地址:湖北省武汉市蔡甸区大学路111号,邮政编码:430100。E-mail:201404152@yangtzeu.edu.cn
  • 基金资助:
    国家自然科学基金“注水吞吐条件下致密油的微观可动机理研究”(42202187)

Spontaneous imbibition and oil displacement characteristics in interlayered shale oil reservoirs and their key controlling factors

FAN Yunpeng1,2(), WEN Zhigang1,2, LI Zhen3, HE You’an3, TIAN Weichao1,2(), LIU Yuhang1,2   

  1. 1. Hubei Key Laboratory of Petroleum Geochemistry and Environment, College of Resources and Environment, Yangtze University, Wuhan, Hubei 430100, China
    2. Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan, Hubei 430100, China
    3. Exploration and Development Research Institute, PetroChina Changqing Oilfield Company, Xi’an, Shaanxi 710018, China
  • Received:2025-02-08 Online:2025-09-19 Published:2025-10-26

摘要:

鄂尔多斯盆地延长组7段(长7段)页岩油是中国典型的夹层型页岩油,现已建成陇东国家级页岩油开发示范基地。自发渗吸排驱油(简称自吸排油)现象贯穿于页岩油储层压裂到原油采出的全过程,对页岩油的产量具有显著影响。明确不同尺寸孔隙中的压裂液自吸排油特征及其控制因素,对于提升长7段页岩油的采收率至关重要。以鄂尔多斯盆地长7段夹层型页岩油储层为研究对象,通过开展孔渗实验、X射线衍射分析、润湿角测定和核磁共振压裂液自吸排油等实验,明确不同类型储层在各尺寸孔隙中的压裂液自吸排油特征,并从物性、矿物组成、润湿性等角度揭示不同类型孔隙自吸排油主控因素。结果表明:①根据核磁共振分形得到的不同类型孔隙占比,可将样品分为Ⅰ类、Ⅱ类储层,Ⅰ类储层大孔占比平均为85.1%,Ⅱ类储层中孔平均占比为79.0%。②Ⅰ类储层的储层品质因子、石英含量高于Ⅱ类储层,黏土矿物含量低于Ⅱ类储层,润湿角范围为77.3°~103.7°,亲水-亲油储层均有发育,Ⅱ类储层样品的润湿角为53.2°~63.1°,均为亲水储层。③Ⅰ类储层平均自吸排油比为17.27%,主要是大孔的贡献,平均为74.1%,中孔贡献的比例为25.5%,Ⅱ类储层平均自吸排油比为40.74%,主要是中孔的贡献,平均为85.2%。综合分析各影响因素,最终认为矿物组成是自吸排油比最根本的影响因素,其次是孔隙类型、润湿性及岩石物性等参数。

关键词: 鄂尔多斯盆地, 夹层型页岩油, 核磁共振, 压裂液自吸排油, 主控因素

Abstract:

The seventh member of the Yanchang Formation (Chang 7 member) in the Ordos Basin is a typical interlayered shale oil reservoir in China. A national shale oil development demonstration base has been established in the Longdong area. Spontaneous imbibition and oil displacement are observed throughout the entire process from hydraulic fracturing to crude oil production, exerting a significant impact on shale oil output. Therefore, clarifying the characteristics of spontaneous imbibition and oil displacement of fracturing fluid in pores of different sizes and their controlling factors is crucial for enhancing shale oil recovery in Chang 7. This study took the interlayered shale oil reservoirs of Chang 7 in the Ordos Basin as a case study. A series of experiments was conducted, including porosity-permeability measurements, X-ray diffraction (XRD) analysis, contact angle determination, and nuclear magnetic resonance (NMR)-based spontaneous imbibition and oil displacement experiments with fracturing fluid. These analyses characterized the spontaneous imbibition and oil displacement behavior of fracturing fluid in pores of different sizes across different reservoir types and revealed their key controlling factors from the perspectives of reservoir physical properties, mineral composition, and wettability. The results showed that: (1) based on pore-type proportions obtained from NMR fractal analysis, the samples were classified into TypeⅠand TypeⅡreservoirs. In TypeⅠreservoirs, macropores made up an average of 85.1%, and in TypeⅡreservoirs, mesopores made up an average of 79.0%. (2) TypeⅠreservoirs exhibited higher reservoir quality factors and quartz content than TypeⅡreservoirs, while containing less clay minerals. Their contact angles ranged from 77.3° to 103.7°, indicating the development of both hydrophilic and lipophilic reservoirs. In contrast, TypeⅡreservoir samples had contact angles between 53.2° and 63.1°, showing strong hydrophilicity. (3) The average spontaneous imbibition and oil displacement ratio in TypeⅠreservoirs was 17.27%, primarily contributed by macropores (74.1% on average), with mesopores accounting for 25.5%. In TypeⅡ reservoirs, the average ratio was 40.74%, primarily attributed to mesopores (85.2% on average). A comprehensive analysis of all influencing factors indicated that mineral composition was the fundamental factor influencing the ratio of spontaneous imbibition and oil displacement, followed by pore type, wettability, and petrophysical properties.

Key words: Ordos Basin, interlayered shale oil, nuclear magnetic resonance, fracturing fluid spontaneous imbibition and oil displacement, key controlling factors

中图分类号: 

  • TE122.2