摘要
近年来,辫状河储层构型精细刻画逐渐成为河流相储层表征的重点与难点。然而,基于露头调研与探地雷达的沉积学模式过于复杂,而基于工程领域的模式推导又往往过于简化,如何将广泛的基础调研运用于工程实践始终是学者们所追求的目标。以4种经典的辫状河模式为基础,结合近年来不同模式的工程应用,将Miall的构型理论缩小到心滩范围并适当增减,探讨了不同岩相和构型要素与心滩的对应关系,提出适用于油藏精细描述的4种辫状河心滩的简易模式。研究认为,垂向加积模式以近水平的落淤层为主要夹层,适用于日常流量较低、洪泛周期较长、洪泛时间不规律、持续时间较短、心滩长期暴露的辫状河体系;辫状-曲流转换模式类似于点坝边滩或边滩的背向拼合,适用于辫状河向曲流河过渡的河型转化带;偏心半椭球模式呈半洋葱状,在垂向加积模式的基础上强化了坝头坝缘坝尾的沉积特征,适用于洪泛周期稳定且河道较深的辫状河体系;复杂构型模式由多种构型要素组合,是偏心半椭球模式的延伸,但划分更细,适用于密集井网的辫状河储层区块。对心滩模式的划分与讨论有利于精细化的勘探开发,而这些模式也可在一定程度上应用于砂质冲积扇、扇三角洲、辫状河三角洲心滩的构型描述当中。
In recent years, the fine characterization of the braided river reservoir configuration has gradually become the focus and difficulty in fluvial facies reservoir characterization. However, the sedimentary patterns based on outcrop research and ground penetrating radar is too complicated, and the derived sedimentary pattern according to engineering is usually too simplified. Scholars continuously purse the goal of how to extensively apply basic summarization to engineering practice. Based on the 4 classic braided river patterns and the engineering applications of different sedimentary patterns in recent years, the Miall configuration theory was reduced to the river island with appropriate complement and simplification to investigate the corresponding relationships between river island and different lithology and configuration elements. In addition, the corresponding sedimentary patterns of four kinds of braided river islands were proposed for fine reservoir characterization. Research indicates that the near-level siltation layer is taken as the major interlayer in the vertical aggradation pattern, which is applicable to the braided river system with low daily flow rate, relatively long flooding cycle, irregular flooding time, short duration time and long-term exposure. The braided-meandering pattern is similar to the backward merging of point marginal bar or point bar, which is suitable for the river transition zone with a transition from braided river to meandering river. The eccentric hemi-ellipsoidal pattern with a half-onion shape shows typical sedimentary features of dam-head, dam-margin and dam-tail on the basis of vertical aggradation pattern, which is applicable for the braided river system with stable flooding cycle and relatively deep channel. The complex configuration pattern is composed of various configuration elements, which is an extension of the eccentric hemi-ellipsoidal pattern by fine subdivision, which is fitting for the braided river reservoir with dense well network. The classification and discussion of river island pattern is favorable to refined exploration and development. These patterns could also be used in the configuration characterization of alluvial fan, fan delta and braided river delta.
作者
陈薪凯
刘景彦
陈程
辛博
仲昭
Chen Xinkai;Liu Jingyan;Chen Cheng;Xin Bo;Zhong Zhao(China University of Geosciences (Beijing), Beijing 100083, China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2019年第2期1-9,共9页
Special Oil & Gas Reservoirs
基金
国家自然科学基金面上项目"海拉尔盆地贝尔凹陷白垩纪多幕裂陷-反转过程的沉积响应及原型盆地恢复"(40972081)
教育部留学回国人员科研启动基金"塔里木盆地志留纪构造活动及其对沉积充填的影响"(2-2-2015-03)
关键词
砂质辫状河
心滩
构型
沉积模式
工程模式
sandy braided river
river island
configuration
sedimentary pattern
engineering pattern
