石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (5): 1646-1663.doi: 10.11743/ogg20250516

• 油气地质 • 上一篇    

典型河口坝沉积演化过程与沉积水动力机制

赵俊威1(), 周健2, 邹俭巍3, 孙海航4, 郑晓丽1, 张明晨1   

  1. 1.长江大学 录井技术与工程研究院,湖北 荆州 434020
    2.中国石化 胜利油田分公司 勘探开发研究院,山东 东营 257000
    3.中国石油 大庆油田分公司 第一采油厂,黑龙江 大庆 163000
    4.中国石油 塔里木油田分公司 油气开发部,新疆 库尔勒 841000
  • 收稿日期:2024-08-07 修回日期:2025-06-06 出版日期:2025-10-30 发布日期:2025-10-29
  • 第一作者简介:赵俊威(1988—),男,博士、副教授、硕士研究生导师,油气藏开发地质、储层沉积学、油藏建模。E-mail:zhaojunwei0201@126.com
  • 基金项目:
    国家自然科学基金项目(41902155);国家自然科学基金项目(41502126)

Exploring the sedimentary evolution processes and hydrodynamic mechanisms of typical mouth bars

Junwei ZHAO1(), Jian ZHOU2, Jianwei ZOU3, Haihang SUN4, Xiaoli ZHENG1, Mingchen ZHANG1   

  1. 1.Institute of Mud Logging Technology and Engineering,Yangtze University,Jingzhou,Hubei 434020,China
    2.Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying,Shandong 257000,China
    3.No. 1 Oil Production Plant,Daqing Oilfield Company,PetroChina,Daqing,Heilongjiang 163000,China
    4.Petroleum Development Division,Tarim Oilfield Company,PetroChina,Korla,Xinjiang 841000,China
  • Received:2024-08-07 Revised:2025-06-06 Online:2025-10-30 Published:2025-10-29

摘要:

河口坝砂体是三角洲沉积体系的重要油气储层,受限于露头、现代沉积及地下储层资料维度、尺度及分辨率,其内部沉积演化过程及构型特征的系统表征一直面临挑战。利用沉积数值模拟技术与现代沉积相结合的方法,分析了典型河口坝的沉积演化过程,建立了河口坝内部构型模式,并深入探讨了发育区的水动力数学模型与机制。研究结果表明:①典型河口坝的沉积演化过程可划分为垂向加积期、前积期、侧向加积期、稳定期及复合河口坝形成期,不同演化阶段的河口坝形态特征存在差异,依次呈现小型长舌状、近菱形状、三角状或“V”状、心滩状和长椭圆状等形态。②河口坝沉积演化过程受水动力变化特征控制,在射流、盆底摩擦力及水体浮力的综合作用下,形成了不同的加积方式与河口坝平面形态。③水动力条件的差异还导致河口坝内部构型模式的分异,其内部加积方式可分为垂积式、前积式及侧积式,单一河口坝不同部位内部构型发育模式具有空间分异性,中心部位以垂向加积为主,前端表现为前积特征,侧翼则呈现侧向披覆及侧向加积特征。本研究为河控三角洲内部河口坝内部构型的精细表征提供了理论依据,对地下河口坝储层构型解析具有一定指导意义。

关键词: 储层构型, 河口坝, 三角洲, 水动力机制, 沉积数值模拟

Abstract:

Mouth-bar sand bodies serve as significant hydrocarbon reservoirs in the deltaic sedimentary system. However, due to the limitations of the dimensions, scales, and resolutions of data on outcrops, modern deposits, and underground reservoirs, the systematic characterization of both the internal sedimentary evolution processes and the architectural characteristics of the mouth-bar sand bodies remains challenging. By integrating sedimentary numerical simulations and modern sediment observations, we analyze the sedimentary evolution of typical mouth bars, reveal their internal architectural patterns, and thoroughly explore the hydrodynamic mathematical models and mechanisms in their development areas. The results indicate that the sedimentary evolution of typical mouth bars can be divided into five stages: vertical aggradation, progradation, lateral aggradation, stabilization, and the formation of composite mouth bars. These mouth bars exhibit varying morphological characteristics across these evolutionary stages, appearing small elongated tongue-shaped, nearly rhombus, triangular or V-shaped, mid-channel bar-shaped, and long ellipse-shaped sequentially. The sedimentary evolution of mouth bars is governed by hydrodynamic variations. The combined action of jets, basin-floor friction, and water buoyancy, results in the formation of varying aggradational styles and diverse planar morphologies of the existing mouth bars. Additionally, variations in hydrodynamic conditions lead to differentiation in the internal architectural patterns of mouth bars. Accordingly, their internal aggradational styles can be classified into vertical aggradation, progradation, and lateral aggradation. For an individual mouth bar, the developmental model of its internal architecture shows spatial differentiation, featuring vertical aggradation-predominated central part, progradation-dominated front end, and lateral draping and aggradation-prevalent side wings. This study provides a theoretical basis for the fine-scale characterization of the internal architectures of mouth bars in fluvial-dominated deltas while also serving as a guide for analyzing the subsurface architectures of mouth-bar reservoirs.

Key words: reservoir architecture, mouth bar, delta, hydrodynamic mechanism, sedimentary numerical simulation

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