石油学报 ›› 2021, Vol. 42 ›› Issue (1): 33-44.DOI: 10.7623/syxb202101003

• 地质勘探 • 上一篇    下一篇

湖泊缓坡带细粒河控三角洲沉积演化和形态特征——沉积正演数值模拟和现代沉积实例的启示

杜威1,2, 纪友亮1,2, 张艺楼3, 周淋4, 吕文睿5, 杨佳奇6, 罗妮娜7, 张宸赫6   

  1. 1. 油气资源与探测国家重点实验室(中国石油大学(北京)) 北京 102249;
    2. 中国石油大学(北京)地球科学学院 北京 102249;
    3. 中国石油化工股份有限公司重庆涪陵页岩气勘探开发有限公司 重庆 408000;
    4. 中海石油(中国)有限公司天津分公司渤海石油研究院 天津 300459;
    5. 中国海洋石油国际有限公司 北京 100027;
    6. 中国地质大学(北京)能源学院 北京 100083;
    7. 中国石油西南油气田公司重庆气矿 重庆 400021
  • 收稿日期:2019-01-04 修回日期:2020-08-03 出版日期:2021-01-25 发布日期:2021-02-05
  • 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:杜威,男,1992年10月生,2015年获西安石油大学资源勘查工程专业学士学位,2018年获中国石油大学(北京)地质工程专业硕士学位,现为中国石油大学(北京)博士研究生,主要从事沉积学、储层地质学和层序地层学方面的研究。Email:sciencedw@163.com
  • 基金资助:
    国家自然科学基金项目(No.41672098,No.42072115)资助。

Depositional evolution and geometrical features of lacustrine fine-grained river-dominated deltas at the gentle slope zone: insights from sedimentary forward numerical modeling and modern case analyses

Du Wei1,2, Ji Youliang1,2, Zhang Yilou3, Zhou Lin4, Lü Wenrui5, Yang Jiaqi6, Luo Nina7, Zhang Chenhe6   

  1. 1. State Key Laboratory of Petroleum Resources and Prospecting(China University of Petroleum), Beijing 102249, China;
    2. College of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China;
    3. Sinopec Chongqing Fuling Shale Gas Exploration and Development Co., Ltd., Chongqing 408000, China;
    4. Bohai Oilfield Research Institute, Tianjin Branch, CNOOC China Limited, Tianjin 300459, China;
    5. CNOOC International Limited, Beijing 100027, China;
    6. School of Energy Resources, China University of Geosciences, Beijing 100083, China;
    7. Chongqing Gas Field, PetroChina Southwest Oil & Gas Field Company, Chongqing 400021, China
  • Received:2019-01-04 Revised:2020-08-03 Online:2021-01-25 Published:2021-02-05

摘要: 细粒三角洲的研究多集中于其深水环境的层序演化,而湖泊缓坡带细粒河控三角洲的短期发育过程、几何形态、沉积模式和砂体展布尚不明确。利用沉积正演数值模拟重塑湖泊缓坡带细粒河控三角洲的生长演化过程,对比分析富粉砂质和富泥质三角洲的形态特征并建立沉积演化模式,结合岱海湖弓坝河三角洲的卫星影像和实地踏勘,研究了实际沉积体系与沉积正演数值模拟的异同,总结砂体展布规律。研究结果表明:(1)湖泊缓坡带的河控细粒三角洲的沉积演化可以划分为正常湖退和强制湖退2种模式。正常湖退背景下,在主分流河道决口分叉的控制下,多期分流河道与河口坝的叠覆体(河坝复合体)经历了增生、废弃和改造的动态过程,最终不均匀地分布于主分流河道两侧。强制湖退背景下,多期岸线的河坝复合体之间由平原主分流河道连接,垂向上形成"三层结构"和"二元结构"交替出现的格局。(2)正常湖退背景下砂泥比影响着河坝复合体与主分流河道的接触关系和三角洲的宏观形态。与富粉砂质三角洲相比,富泥质三角洲具有"规模大、延伸广和节点发育"的特点。(3)受三角洲形态特征的影响,与富粉砂质三角洲相比,富泥质三角洲砂体延伸远但相对孤立,连通性较差,与烃源岩联系更密切。正常湖退和强制湖退的交替出现增强了砂体的非均质性。

关键词: 浅水曲流河三角洲, 河坝复合体, 砂体形态, 岱海湖, 高频湖平面变化

Abstract: Researches on fine-grained deltas mostly focus on the sequence evolution of their deep-water environment. However, the short-term development process, geometric form, deposition mode and sand body distribution of fine-grained river-dominated delta in the gentle slope of lakes are still unclear. Using sedimentary forward numerical simulation, this paper rebuilds the growth and evolution process of fine-grained river-dominated delta in the gentle slope of lakes, contrasts and analyzes the morphological characteristics of silt-rich and shale-rich deltas, and establishes a depositional evolution model. In combination with the satellite imagery and field surveys of Gongba river delta in the Daihai lake, the paper studies the similarities and differences between the actual sedimentary system and the sedimentary forward numerical simulation results, and summarizes the distribution law of sand body. The research results show that:(1) The sedimentary evolution of the river-dominated fine-grained delta in the gentle slope of lakes can be divided into two modes:normal lacustrine regression and forced lacustrine regression. During normal lacustrine regression, under the control of the crevasse and bifurcation of the main distributary channel, the superimposed bodies of the multi-stage distributary channel and the mouth bar (channel-mouth bar complexes) underwent a dynamic process of accretion, abandonment and transformation, and finally were unevenly distributed on both sides of the main distributary channel. During forced lacustrine regression, the distributary channel-mouth bar complexes of the multi-stage strandline are connected by the main distributary channel in a delta plain, forming a vertically-alternating pattern of "three-layer structure" and "dual structure". (2) The sand-mud ratio during normal lacustrine regression affects the contact relationship between the distributary channel-mouth bar complex and the main distributary channel, as well as the macroscopic morphology of the delta. Compared with the silt-rich delta, the shale-rich delta has the characteristics of "large scale, wide extension and node development". (3) Affected by the morphological characteristics of deltas, compared with silt-rich deltas, the sand bodies of shale-rich deltas extend farther but are relatively isolated, have poor connectivity, and are more closely related to source rocks. The alternation of normal and forced lacustrine regression enhances the heterogeneity of sand bodies.

Key words: shallow-water meandering river delta, channel-mouth bar complex, sand body geometry, Daihai lake, high-frequency lake level change

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