西南石油大学学报(自然科学版) ›› 2019, Vol. 41 ›› Issue (1): 1-17.DOI: 10.11885/j.issn.1674-5086.2018.01.01.01

• 地质勘探 •    下一篇

砂砾岩储层孔隙结构复杂模态差异机制

印森林1, 陈恭洋1, 陈玉琨2, 吴小军2   

  1. 1. 长江大学录井技术与工程研究院, 湖北 荆州 434023;
    2. 中国石油新疆油田分公司勘探开发研究院, 新疆 克拉玛依 834000
  • 收稿日期:2018-01-01 出版日期:2019-02-10 发布日期:2019-02-10
  • 通讯作者: 印森林,E-mail:yinxiang_love@qq.com
  • 作者简介:印森林,1983年生,男,汉族,湖北仙桃人,副教授,博士,主要从事油气田开发地质、录井地质方面的研究和教学工作。E-mail:yinxiang_love@qq.com;陈恭洋,1963年生,男,汉族,湖北潜江人,教授,博士,主要从事石油地质与录井地质方面的研究和教学工作。E-mail:gychen8888@126.com;陈玉琨,1983年生,男,汉族,河南灵宝人,高级工程师,博士,主要从事储层开发地质及提高采收率方面的研究工作。E-mail:cyk_117@petrochina.com.cn;吴小军,1976年生,男,汉族,四川安岳人,高级工程师,学士,主要从事油气田开发研究工作。E-mail:wuxiaojun@petrochina.com.cn
  • 基金资助:
    国家自然科学基金(41502126);长江大学青年基金(2015cqn55)

Mechanism of Complex Modes of the Pore Structure of Sandstone/Conglomerate Reservoirs

YIN Senlin1, CHEN Gongyang1, CHEN Yukun2, WU Xiaojun2   

  1. 1. Institute of Mud Logging Technology and Engineering, Yangtze University, Jingzhou, Hubei 434023, China;
    2. Research Institute of Exploration and Development, Xinjiang Oilfield Company, CNPC, Karamay, Xinjiang 834000, China
  • Received:2018-01-01 Online:2019-02-10 Published:2019-02-10

摘要: 针对砂砾岩储层孔隙结构复杂、模态成因机制不明的情况,以325块岩芯分析化验数据为基础,利用压汞、铸体薄片、扫描电镜及X射线-CT扫描等方法,开展了岩石相分类、孔隙结构模态和驱油效率差异机制的研究,从油田开发与实用相结合的方式考虑,将砂砾岩储层岩相分为3大类、7亚类、13细类。研究表明:不同孔隙结构模态特征及注水驱替效率差异较大。单模态岩石颗粒以粗砂岩为主,孔隙发育程度高,孔隙呈网络状结构,相互连通性较好,注水驱替模式以网络状连通驱替为主,效率较高。双模态岩石颗粒由砾岩和中-粗砂岩两级颗粒组成,孔隙较发育,孔隙呈疏网状结构,相互连通性一般,注水驱替模式以星点状连通驱替为主,效率一般。复模态岩石颗粒由砾石、中-粗砂岩、粉砂或泥质三级颗粒组成,孔隙发育一般,孔隙呈星点状结构,相互连通较差,注水驱替模式以零星散乱状驱替为主,局部存在高渗带,效率整体较差。相同岩相呈不同孔隙结构模态和不同的岩相呈相同的结构模态的情况普遍存在。颗粒排列方式及成岩作用差异改造导致了同相异态,而颗粒分选、磨圆、排列方式等因素形成了异相同态。

关键词: 砂砾岩储层, 孔隙结构, 复模态, 冲积扇, 岩石相, 驱油效率

Abstract: The formation mechanism of complex modes of the pore structure of sandstone/conglomerate reservoirs is still unclear. Thus, this study investigated the difference mechanisms of lithofacies classification, pore structure modes, and displacement efficiencies based on experimental data of 325 core examples through mercury intrusion porosimetry, cast thin sections, scanning electron microscopy, and X-ray computed tomography. The results reveal that, taking both oil field exploitation and utility into consideration, lithofacies of sandstone/conglomerate reservoirs can be classified to 3 primary categories, 7 secondary categories, and 13 tertiary categories. They have different pore structure modal characteristics and relatively great variance in their efficiency of displacement by water injection. Single-mode rock particles are mostly coarse sandstones with highly developed and relatively well inter-connected pores in a network structure. The displacement by water injection is mainly via connected networks, resulting in higher efficiency. Dual-mode rock particles are composed of two classes of particles:conglomerates and medium-coarse sandstones. They have relatively developed and moderately inter-connected pores in a sparse network structure. The displacement, here, is mainly via star-shaped connected networks, with ordinary efficiency. Complexmode rock particles consist of three types of particles:conglomerates, medium-coarse sandstones, and silt or mud. Their pores are moderately developed and relatively poorly inter-connected with a star-shaped networking structure. The water injectiondriven displacement is mostly scattered over local high-permeability zones, resulting in poor overall efficiency. The same lithofacies typically show different pore structure modes while different lithofacies can have identical structure modes. Differential transformation due to particle configuration and diagenesis leads to different pore structure modes for identical lithofacies; while sorting, rounding, and arrangement of particles result in identical pore structure modes for different lithofacies.

Key words: sandstone/conglomerate reservoir, pore structure, complex mode, alluvial fan, lithofacies, displacement efficiency

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