歧口凹陷歧深地区沙三段沉积体系演化特征及沉积模式  

Sedimentary evolution characteristics and sedimentary model of the third member of Shahejie Formation in Qishen area of Qikou Sag

作　　者：杜民[1] 苏俊青[2] 陆永潮[3] 陈雷[3] 帅庆伟[1] 

机构地区：[1]广州海洋地质调查局国土资源部海底矿产资源重点实验室,广东广州510760 [2]中国石油大港油田分公司勘探开发研究院,天津300280 [3]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074

出　　处：《地学前缘》2013年第5期139-148,共10页Earth Science Frontiers

基　　金：中国石油天然气股份有限公司重大专项课题(2008E-0601)

摘　　要：通过岩心观察结果,结合钻井、测井及地震等资料,对歧深地区沙三段沉积特征进行了研究。结果表明:研究区沙三段主要发育4种沉积体系,即辫状河三角洲沉积体系、水下扇沉积体系、扇三角洲沉积体系和湖泊沉积体系。以单井沉积研究为基础,参考地震相与属性分析,同时结合砾岩厚度图、含砂率图及累计砂厚度图,编制了沙三段的沉积体系分布图,再现了歧深地区沙三段各层段的沉积体系空间展布特征。研究得出:歧深地区主要物源来自南部周清庄、西北部沈清庄及北部小站—葛沽;从盆缘至凹陷中心,研究区沙三段沉积体系分布属传统断陷湖盆充填模式,但以发育大规模远岸水下扇沉积为典型特征;歧深地区不同类型的构造-古地貌控制着沉积体系类型及其展布特征,而断层转换带则影响着沉积砂体的再分配。远岸水下扇的浊流水道为研究区最有利的储集相带,辫状河三角洲前缘的水下分流河道及河口坝次之,而扇三角洲前缘的河口坝及水下河道砂体再次。According to core observation and considering drilling, well logging and seismic data, the sedimenta- ry characteristics of the third member of Shahejie Formation in the Qishen area have been researched. The results show that four types of depositional systems composed of braided river delta, subaqueous fan, fan delta and lacustrine depositional system were developed in the third member of Shahejie Formation. Based on sedi- mentary lithofacies analysis of each borehole, taking seismic facies and attribute into account, and combined with conglomerate thickness, sand content rate and sand thickness, the sedimentary systems maps were made, in which the temporal and spatial distribution characteristics of each segment in the third member of Shahejie Formation were reconstructed in the Qishen area. The studies indicate that the dominate sources were from ghouqinzhuang of the south, Shenqingzhuang of the northwest, and Xiaozhan-Gegu of the north. The distribu- tion of sedimentary systems of the third member of Shaheiie Formation in the Qishen area follows traditional filling model of fault basin, nevertheless extensive distal subaqueous fan is the representative characteristic in this study area. In the Qishen area, the types of depositional systems and their distribution are controlled by different types of structure-paleogeomorphology, whereas the fault transform zones dominate the redistribution of sand bodies. In the study area, the turbid channel deposits of distal subaqueous fan are the most favorable reservoir facies, followed by the underwater distributary channel and mouth bar deposits of braided river delta front, then the mouth bar and underwater distributary ehannd deposits of fan delta front are the third advantageous reservoir facies.

关 键 词：沉积体系 沉积模式 沙三段 歧深地区 

分 类 号：P618.130.2[天文地球—矿床学]