渤海湾盆地东营凹陷胜坨地区沙四上亚段物源方向对储集砂体的控制作用

综合地震、测录井及地化分析资料，在古地貌分析的基础上，根据岩屑组合特征、特征元素比值分布模式以及砂砾岩百分含量等参数，对渤海湾盆地东营凹陷胜坨地区沙四上亚段物源方向和砂体类型进行了分析。沙四上亚段沉积时期，胜坨地区存在两个不同的物源体系，即坨94断层上升盘物源和胜北断层上升盘物源。在这两个物源体系的控制下，主要发育近岸水下扇、湖底扇、沟道浊积岩等不同类型的砂砾岩体。其中，近岸水下扇主要发育在陈南断层下降盘，湖底扇主要发育坨94断层和胜北断层下降盘，沟道浊积岩发育在胜北断层形成的断槽中。砂砾岩体以辫状水道和沟道浊积岩储层物性最好，其主要的储集空间为裂缝和溶蚀孔隙形成的孔缝复合系统。因此，辫状水道成为油气富集的有利相带。

Provenance systems and their control over sandbodies in the upper Es4 of the Shengtuo area in the Dongying Sag,the Bohai Bay Basin

An analysis of the provenances and sandbody types of the upper4 th member of Eogene Shahejie Formation（Es 4 ）in the Shengtuo area of the Dongying Sag，the BohaiBay Basin was carried out based on an integration of seism ic，logging and geochem ical data，a paleogeomorphologic analysis，and a study of lithic fragment assemblage，ratio of characteristic elements and net-to-gross ratio.The results indicate that there were two different provenance systems during the deposition of the upper Es 4 :one on the upthrow of the Tuo94fault and the other on the upthrow of the Shengbei fault.Controlled by these two systems，various types of sandbodieswere developed in the area，including nearshore subaqueous fan，sublacustrine fan and channel turbidite.The nearshore subaqueous fansmainly occur on the downthrow of the Chennan fault，the sublacustrine fansmainly occur on the downthrows of the Tuo94fault and the ShengbeiFault，while the channel turbidites occur in the trough along the Shengbei fault.It is suggested that the braided channel sandbodies and channel turbidite have the bestporoperm characteristics，and their reservoir space is composed of fractures and dissolved pores.Therefore，the braided channel is a favorable facies belt for oil and gas accumulation.