柴达木盆地全吉剖面第四系七个泉组沉积特征及沉积模式  

Sedimentary characteristics and model of Quaternary Qigequan Formation in Quanji section of Qaidam Basin

作　　者：栾守亮[1] LUAN Shou-liang(Exploration and Development Research Institute of Sinopec Shengli Oilfield Company,Dongying 257015,China)

机构地区：[1]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《天然气地球科学》2020年第6期800-808,共9页Natural Gas Geoscience

基　　金：中国石化股份公司项目“柴达木盆地中石化区块成藏条件与勘探潜力评价”(编号:P18054-1)资助。

摘　　要：通过对柴达木盆地全吉地区露头剖面进行详细观察和精细测量,详细分析了地层特征、沉积相类型及演化规律。结果表明:研究区七个泉组存在浅湖沉积的证据,七个泉组岩石粒度下部较细,向上部逐渐变粗,主要发育湖泊、滩坝与扇三角洲3种沉积相类型,整体为水退的沉积过程;湖泊相岩性以滨湖和浅湖泥质粉砂岩为主,夹有塑性变形构造丰富的含砾粗砂岩、中粗砂岩,属于风暴沉积产物;将滩坝相进一步划分为远岸坝砂、近岸滩砂与泥滩亚相,坝砂亚相的岩性多为灰色中、厚层砂岩夹透镜状泥岩,滩砂亚相的岩性以中薄层的粉细砂岩为主;扇三角洲相的岩性以厚层灰色砾岩、中粗砂岩为主。通过对该剖面多个出露点的沉积相对比分析,明确了沉积相在横向的变化规律和滩坝砂体空间展布规律,首次建立了该区的滨、浅湖滩坝砂沉积模式。In this paper,through detailed observation and fine measurement of outcrop profile in Quanji area of Qaidam Basin,the stratigraphic characteristics,sedimentary facies types and evolution rules are analyzed in detail.The results show that there is evidence for shallow lake sedimentation in the Qigequan Formation in the study area.Grain size of the rock from the lower part of the Qigequan Formation is fine,and gradually coarse to the upper part.There are mainly three types of sedimentary facies:Lake,beach bar and fan delta,which are in the whole process of retrograde sedimentation.The lake is mainly composed of lakeside and shallow lake argillaceous siltstone,with gravel bearing coarse sandstone and medium coarse sandstone with rich plastic deformation structure,belonging to the storm sediment products.The beach bar is further divided into distal bar sand,nearshore bar sand and mudflat.The bar sand is shown as gray medium and thick sandstone with lenticular mudstone.The beach sand is mainly composed of medium thin layer of siltstone;the fan delta is mainly composed of thick layer of gray conglomerate and medium coarse sandstone.Based on the comparative analysis of the sedimentary facies of several dew points in the profile,the lateral change law of the sedimentary facies and the spatial distribution law of beach bar sand body are clarified,and the beach bar sand sedimentary model of the area is established for the first time.

关 键 词：柴达木盆地 全吉剖面 七个泉组 沉积相 沉积模式 

分 类 号：TE121.3[石油与天然气工程—油气勘探]