南堡凹陷高尚堡地区东营组下切谷特征及意义

通过地震反射特征、沉积、层序地层和构造背景等综合分析,在南堡凹陷高尚堡地区东营组地层中识别出一套下切谷沉积。研究发现:高尚堡下切谷形成于盆地陡坡带一侧断裂坡折带上,在地震剖面上表现为宽缓的U型反射特征,谷内外同相轴明显不协调,岩性以粗碎屑为主;湖平面的快速下降和断层是控制该下切谷形成的关键因素。高尚堡下切谷紧靠油源断层,上倾方向被反向断层切割,为油气富集创造了良好条件,与该下切谷有关的油藏类型主要有地层超覆不整合油藏、断层—岩性复合油藏、砂岩透镜体油藏。该下切谷的发现,对南堡凹陷高尚堡地区的层序边界划分、地层对比和储层预测具有重要意义。

Characteristics and significance of Dongying Formation incised valley in Gaoshangpu area,Nanpu Sag

Through overall analyzing seismic reflection characteristics,deposition,sequence stratigraphy and structural background,an incised valley deposit is recognized in Dongying Formation in Gaoshangpu area,Nanpu Sag.Formed on a fault slope break of the basin steep slope side,this incised valley is characterized by U-shape on seismic sections with obviously uncoordinated events.And the valley consists of mainly coarse clastics.The rapid lake level falling and faults were key factors to control the incised valley formation.Close to the source faults,Gaoshangpu incised valley was cut off by an antithetic fault in the updip direction, which provides favorable conditions for the hydrocarbon enrichment.Reservoirs associating with the valley include overlap unconformable reservoir, faulted-lithologic composite reservoir and sand lens reservoir.This incised valley has important significance in sequence boundary identification,formation correlation and reservoir prediction in Gaoshangpu area,Nanpu Sag.