青海湖北部冲积扇沉积特征、演化过程及控制因素

发布时间：2018-03-16 22:31

本文选题：冲积扇　切入点：沉积特征　出处：《油气地质与采收率》2017年05期 　论文类型：期刊论文

【摘要】：冲积扇是重要的油气储集体,具有内部结构复杂、非均质性强的特点。通过野外剖面实测、遥感影像分析等方法,对位于青海湖北部的3个冲积扇(泉吉河扇、沙柳河扇和烂泥湾扇)进行沉积亚相的划分和沉积微相的识别。对于泉吉河扇和沙柳河扇,在扇根亚相中识别出辫状河道、主水道和主水道间微相,在扇中亚相中识别出辫状河道、心滩、漫流微相和低粘度碎屑流沉积,在扇缘亚相中识别出漫流微相和泥滩微相。烂泥湾扇发育2期泥石流作用和短暂的牵引流作用。根据沉积特征将沙柳河扇和泉吉河扇的沉积演化过程划分为4个阶段,分别为初次碎屑流沉积及主水道发育阶段、低粘度碎屑流沉积阶段、广泛的辫状河道发育阶段、河道迁移及三角洲发育阶段。将烂泥湾扇的沉积演化过程划分为3个阶段,分别为早期泥石流沉积阶段、间歇期牵引流沉积阶段和后期泥石流沉积阶段。研究结果表明,物源条件的差异是造成研究区3个现代冲积扇沉积特征差异的主要原因,气候条件中的湿度和风场对青海湖北部冲积扇的沉积也具有一定的控制作用。
[Abstract]:Alluvial fan is an important oil and gas reservoir with complex internal structure and strong heterogeneity. Three alluvial fans (Quangji River fan) located in the northern part of Qinghai Lake were studied by field profile measurement and remote sensing image analysis. For the Quangji River fan and the Shaliu fan, the braided channel, the microfacies between the main waterway and the main waterway are identified in the fan root subfacies. The braided channel, core beach, diffuse microfacies and low viscosity clastic flow deposits were identified in the central facies of fan. The diffuse microfacies and mudflat microfacies were identified in the subfacies of fan margin. The debris flow and the transient tractive flow in the second stage of the development of the muddy bay fan were identified. According to the sedimentary characteristics, the sedimentary evolution of the Shaliuhe fan and the Quanji river fan were divided into four stages. The sedimentary evolution of the muddy bay fan is divided into three stages: the primary clastic flow deposition and the main channel development stage, the low viscosity detrital flow deposition stage, the extensive braided channel development stage, the channel migration stage and the delta development stage. The results show that the difference of provenance conditions is the main reason for the difference of sedimentary characteristics of the three modern alluvial fans in the study area. The humidity and wind fields in climatic conditions also control the deposition of alluvial fans in the northern part of Qinghai Lake.
【作者单位】：中国地质大学(北京)能源学院;中国石化勘探分公司勘探研究院;
【基金】：国家科技重大专项“陆相深水储集体成因与地质评价新方法”(2017ZX05009-002)
【分类号】：P618.13

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