地学前缘 ›› 2025, Vol. 32 ›› Issue (6): 350-366.DOI: 10.13745/j.esf.sf.2025.8.67

• 岩石成因与效应新探 • 上一篇    下一篇

沉积层序中的时空分形结构及其地质意义

阮壮1(), 王玥蕴2, 常秋红1, 于炳松1,*()   

  1. 1.中国地质大学(北京)地球科学与资源学院, 北京 100083
    2.中国石油天然气股份有限公司西南油气田分公司勘探开发研究院, 四川 成都 610041
  • 收稿日期:2025-05-20 修回日期:2025-06-13 出版日期:2025-11-25 发布日期:2025-11-12
  • 通信作者: 于炳松
  • 作者简介:阮 壮(1983—),男,副教授,博士生导师,主要从事沉积学研究。E-mail: ruanz0103@cugb.edu.cn
  • 基金资助:
    国家自然科学基金面上项目(42272136);国家自然科学基金面上项目(42102162);国家自然科学基金青年项目(42302177);云南省科技厅重大项目(202303AA080006-01)

Spatio-temporal fractal structures in sedimentary sequences and their geological significance

RUAN Zhuang1(), WANG Yueyun2, CHANG Qiuhong1, YU Bingsong1,*()   

  1. 1. School of Geosciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
    2. Exploration and Development Research Institute, PetroChina Southwest Oil & Gasfield Company, Chengdu, 610041, China
  • Received:2025-05-20 Revised:2025-06-13 Online:2025-11-25 Published:2025-11-12
  • Contact: YU Bingsong

摘要:

沉积层序的形成受控于构造活动、海(湖)平面变化及气候演化等多种地质过程,其时空结构复杂且具有多尺度性。传统方法难以揭示其内在规律,而分形理论为研究沉积层序提供了新的视角。本研究基于分形理论,以济阳坳陷沙河街组为例,系统分析了沉积层序的时空分形结构及其地质意义。首先,利用Hurst指数量化沉积层序的时间分形特征,并探讨其在沉积环境演化过程中的应用。其次,通过功率谱分析,揭示储层沉积系统的自组织临界性,并提出基于滤波方法的长程时-空关联结构提取技术。最后,研究了孔隙结构的分形特征,并量化评价其对储层渗透性的影响。研究结果表明,Hurst指数可用于定量刻画沉积环境的长期演化趋势,储层自组织临界性可用于优化储层参数分析,而分形理论在储层孔喉结构评价中具有重要应用价值。本研究不仅深化了对沉积层序复杂性的理解,也为油气资源的勘探和储层评价提供了新的理论支持和方法。

关键词: 分形理论, 时空分形结构, Hurst指数, 功率谱分析, 孔喉结构评价

Abstract:

The formation of sedimentary sequences is controlled by tectonic activity, sea (lake)-level change, and climate evolution, resulting in complex multiscale spatiotemporal structures. While traditional methods struggle to reveal their intrinsic patterns, fractal theory offers a novel approach. Using the Shahejie Formation in the Jiyang Depression as a case study, this research systematically analyzes the spatiotemporal fractal structures of sedimentary sequences and their geological implications. First, the Hurst index quantifies temporal fractal characteristics to interpret sedimentary environment evolution. Second, power spectral density analysis reveals self-organized criticality (SOC) of the sedimentary system, and a filter-based technique for extracting long-range spatiotemporal correlations is proposed. Finally, fractal dimensions of pore structures are characterized to quantitatively evaluate their impact on reservoir permeability. Results demonstrate that: (1) The Hurst index quantifies long-term sedimentary trends; (2) SOC optimizes reservoir parameter analysis; (3) Fractal theory critically supports pore-throat structure evaluation. This study advances understanding of sedimentary complexity and provides new theoretical/methodological foundations for hydrocarbon exploration and reservoir assessment.

Key words: fractal theory, spatio-temporal fractal structure, Hurst index, power spectrum analysis, pore throat structure evaluation

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