松辽盆地南部泉四段物源判别与沉积特征  

Sedimentary characteristics and provenance identification in section 4 of Quantou formation in south of Songliao Basin

作　　者：张鑫 

机构地区：[1]中海油研究总院,北京100027

出　　处：《大庆石油学院学报》2011年第5期16-21,114,共6页Journal of Daqing Petroleum Institute

基　　金：国家科技支撑计划项目(2006BAC18B05)

摘　　要：根据岩心观察和描述,结合测井、区域地质、分析化验资料及砂体平面分布特征,分析松辽盆地南部泉四段的物源及沉积体系.结果表明:研究区泉四段沉积环境气候干燥,没有统一的汇水中心,主要发育河流—末端扇沉积体系.河流相主要包括辫状河与曲流河,辫状河沉积分布在盆地边缘地带,向盆地中心逐渐过渡为曲流河沉积;随着地形坡度逐渐变缓,曲流河末端流量消减,河道呈分散状大量分叉,水流向四周散开,宽而浅的河道向扇体转变,形成末端扇沉积.研究区末端扇沉积分为近端亚相、中部亚相和远端盆地.近端亚相沉积微相包括补给河道与河道间,中部亚相沉积微相包括分流河道、河道漫溢与泥滩.末端扇沉积层序与曲流河难以区分,但末端扇平行层理非常发育,且末端扇平面几何形态与曲流河不同.曲流河的古流向一般是单向的,而末端扇古水流呈扇形发散,砂体形态呈扇形或朵状.The provenance and sedimentary system in section 4of Quantou formation in south of Songliao Basin is studied according to core observation and description combined with the numerous data of logging,regional geology and planar distribution characteristics of sandstones.The result shows that sedimentary environment is dry in section 4 of Quantou formation,and there is no unified catchment in this area.The stream terminal fan is the major depositional system.The fluvial facies include braided stream and meandering stream.The braided streams develop on the basin margin and become meandering stream gradually towards the central basin.The flow of the termination of meandering stream tapers off with terrain slope becoming flat gradually.The channels scatter with shape bifurcation,the water flow spread around,the wide shallow channel change to fan body,and the terminal fan deposit formed.The terminal fan in this area is divided into proximal subfacies,middle subfacies and distal basin.The microfacies of proximal subfacies includes supplies channel and interchannel.The microfacies of middle subfacies includes distributary channel,verflow and mudflat.The sedimentary sequence of terminal fan is difficult to distinguish with meandering stream,but the parallel bedding is well developedt in terminal fan and the plane geometry shape is different from meandering stream.The ancient flow of meandering stream is generally one-way,but the ancient flow of terminal fan is divergent in fan-shaped,and the sandstone is fan-shaped or flower shaped.

关 键 词：松辽盆地 辫状河 曲流河 末端扇 沉积体系 

分 类 号：TE121.3[石油与天然气工程—油气勘探]