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由于对柳赞地区沙三段物源发育方向认识单一,导致对砂体发育特征和岩性圈闭分布模式的认识与钻探结果不完全相符,从而制约了本区进一步精细勘探挖潜.针对该问题,本文通过进行柳赞地区沙三段中下部层序地层格架分析,重新认识沙三段中下部物源发育特征,建立柳赞地区沙三段中下部砂体发育模式.取得以下4项研究新进展:1)发现柳赞沙三段中下部地层中层序3底面典型的下超(过去被解释为上超)地震不整一现象;2)通过岩心相和地震相分析识别出了近岸水下扇,建立了陡坡带两种储集相模式;3)利用典型地震相识别、重矿物分析等技术,发现柳赞地区沙三段沉积早中期由层序1-层序2的东部小型物源演变为层序3北西大型物源,改变了沙三段只发育北东向物源的传统认识;4)基于对层序地层格架和沉积相发育的研究,建立了柳赞地区沙三段中下部砂岩体发育模式,指明岩性圈闭勘探的重要方向.上述研究新进展不仅对老区挖潜有重要指导意义,而且深化了陆相断陷盆地陡坡带强烈构造运动控制物源迁移和砂岩体分布规律的认识.“,”It is unclearly that the development direction of provenance controls on the development characteristics and distribution model of sandbodies,which restricts the hydrocarbon exploration.To resolve the problems,the studies on the development characteristics of provenance and the distribution of sedimentary facies are depicted,based on the third-order sequence stratigraphic framework.The results indicated that:1) the typical downlap is identified in SQ Ⅲ,which was interpreted as onlap in the past;2) nearshore subaqueous fan is recognized according to the analysis of seismic facies and core data,which enriches the depositional facies types in steep slope zone;3) different from the east provenance in the SQⅠ and SQⅡ,the sediment supply comes from the northwestern part lead to the large fan-delta development,which is changed the traditional viewpoint about the northeastern provenance;4) based on the sedimentary facies analysis in sequence stratigraphic framework,the sandbody development model from SQ Ⅰ to SQⅢ in the study area is established.This study provides guidance to the hydrocarbon exploration in mature oildfields and implicates the provenance controls on the sediments partition in steep slope zone of lacustrine rift basin.