石油学报 ›› 2017, Vol. 38 ›› Issue (8): 876-887.DOI: 10.7623/syxb201708003

• 地质勘探 • 上一篇    下一篇

致密砂岩孔喉大小表征及对储层物性的控制——以鄂尔多斯盆地陇东地区延长组为例

吴浩1, 张春林2, 纪友亮1, 刘锐娥2, 曹尚3, 陈胜2, 张云钊1, 王晔1, 杜威1, 刘刚4   

  1. 1. 中国石油大学地球科学学院 油气资源与探测国家重点实验室 北京 102249;
    2. 中国石油勘探开发研究院天然气地质研究所 河北廊坊 065007;
    3. 陕西延长石油(集团)有限责任公司研究院 陕西西安 710075;
    4. 浙江大学海洋学院海洋地质与资源研究所 浙江杭州 310058
  • 收稿日期:2016-12-28 修回日期:2017-05-25 出版日期:2017-08-25 发布日期:2017-09-02
  • 通讯作者: 纪友亮,男,1962年10月生,1983年获华东石油学院学士学位,1991年获石油大学(北京)博士学位,现为中国石油大学(北京)教授、博士生导师,主要从事沉积学、储层地质学和层序地层学方面的科研和教学工作。Email:jiyouliang@cup.edu.cn
  • 作者简介:吴浩,男,1990年11月生,2012年获中国矿业大学学士学位,2015年获中国矿业大学硕士学位,现为中国石油大学(北京)博士研究生,主要从事储层地质学方面的研究。Email:H.Wu1990@outlook.com
  • 基金资助:

    国家自然科学基金项目(No.41272157)、国家重大科技专项(2011ZX05007-003,2016ZX05006-006)和中国石油天然气股份有限公司重大科技专项(2011E-2602)资助。

Pore-throat size characterization of tight sandstone and its control on reservoir physical properties:a case study of Yanchang Formation,eastern Gansu,Ordos Basin

Wu Hao1, Zhang Chunlin2, Ji Youliang1, Liu Rui'e2, Cao Shang3, Chen Sheng2, Zhang Yunzhao1, Wang Ye1, Du Wei1, Liu Gang4   

  1. 1. College of Geosciences, China University of Petroleum;State Key Laboratory of Petroleum Resources and Prospecting, Beijing 102249, China;
    2. Natural Gas Geological Department, PetroChina Research Institute of Petroleum Exploration and Development, Hebei Langfang 065007, China;
    3. Research Institute of Shaanxi Yanchang Petroleum(Group) Co. Ltd., Shaanxi Xi'an 710075, China;
    4. Institute of Marine Geology and Resource, Ocean College, Zhejiang University, Zhejiang Hangzhou 310058, China
  • Received:2016-12-28 Revised:2017-05-25 Online:2017-08-25 Published:2017-09-02

摘要:

孔喉大小是评价储层质量的重要因素,而致密砂岩储层孔喉分布较强的非均质性使其表征难度较大。在分析目前孔喉表征方法的基础上,通过场发射扫描电镜、高压压汞和恒速压汞等实验,研究了鄂尔多斯盆地陇东地区延长组7段致密砂岩储层孔喉大小分布特征及其对储层物性的控制作用。结果表明:储层孔隙类型主要为剩余粒间孔、溶蚀孔、微孔和少量微裂缝;高压压汞表征孔喉的大小分布在0.014 8~40 μm,大于1 μm的孔喉分布较少;恒速压汞测试表明对于不同物性的样品其孔隙半径分布相对集中,主要分布在80~350 μm;喉道半径则表现出较强的非均质性,分布在0.12~30 μm;高压压汞和恒速压汞结合有效地表征了致密砂岩储层整个孔喉分布特征,孔径分布在0.014 8~350 μm。储层渗透率主要由比例较小的大孔喉(大于R50)所控制,对于渗透率大于0.1 mD的致密砂岩,其渗透率主要由微孔和中孔所控制,而小于0.1 mD的致密砂岩则主要由纳米孔和微孔所控制;此外,小孔喉的比例随着渗透率的减小而增加,虽然其对渗透率影响较小,但对储层储集性的影响却十分重要。

关键词: 致密砂岩, 孔喉大小, 延长组, 鄂尔多斯盆地, 陇东地区

Abstract:

Pore-throat size is a key factor to evaluate reservoir quality, whereas the strong heterogeneity of pore-throat in tight reservoirs leads to a large difficulty in characterization. Based on analyzing the current pore-throat characterization methods, the experiments of field emission scanning electron microscope, high-pressure mercury injection(HPMI) and constant-rate mercury injection(CRMI) are performed to study the pore-throat size characteristics of tight reservoirs in 7th Member of Yanchang Formation, eastern Gansu, Ordos Basin and their control on reservoir physical properties. The results show that reservoir pore types mainly include residual intergranular pores, dissolution pores, micropores and a few micro-fractures. Pore-throat sizes characterized by HPMI range from 0.014 8-40 μm, and the pore-throats with the radius >1 μm are rare. The CRMI test reveals that for the samples with different physical properties, their pore radius distribution is relatively concentrated, ranging between 80 and 350 μm, whereas throat radius presents a strong heterogeneity, distributed between 0.12 and 30 μm. The overall pore-throat size distribution characteristics of tight reservoir are effectively characterized by integrating the HPMI and CRMI methods, and the pore sizes are found to range from 0.014 8 to 350 μm. Reservoir permeability is mainly controlled by large pore-throats(>R50) with a small proportion. As for the tight sandstone with the permeability greater than 0.1 mD, the permeability is dominated by micropores and mesopores, while the tight sandstone with the permeability smaller than 0.1 mD is mainly controlled by nanopores and micropores. In addition, the proportion of small pore-throats increases with the decrease of permeability. Although their impacts on permeability are small, they play an important role in contributing the reservoir porosity.

Key words: tight sandstone, pore-throat size, Yanchang Formation, Ordos Basin, eastern Gansu

中图分类号: