埕岛地区中浅层河流相砂体输导性研究——以渤海海域埕岛地区新近系为例

Migration performance of fluvial sand body in middle-shallow layers of Chengdao district

河流相砂体是埕岛地区中浅层主要的油气输导层和储集层,研究其输导性对油气勘探具有重要意义。研究认为,断层相连是中浅层河流相砂体输导油气的前提,构造背景影响着油气输导方向;河道沉积砂体输导性最好,堤岸沉积砂体次之,泛滥平原沉积的砂体最差。不同岩性中细砂岩输导性最好,中砂岩次之,粉砂岩第三;输导砂体物性下限随着埋深增加而减少;砂体连通性越好,输导性越好。根据砂体宏观连通基本类型,建立了厚砂体直接连通型、微断层连通型和薄砂体或物性较差砂体连通型三种输导模式,并提出中浅层河流相砂体输导性的评价思路。

Fluvial sand body is the main carrier bed and reservoir in middle-shallow layers of Chengdao district. The results indicate whether the channel and source fault are connected is the premise of hydrocarbon migration in Fluvial sand body and the structural background influences the direction of hydrocarbon migration. The transporting capacity of sand body in river channel is the best, embankment is the secondary, floodplain sediment is the worst, the transporting capacity of fine-grained sandstone is the best, sandstone is the secondary and the siltstone was the third. The physical properties of the lower limit of migration sand decreases with the increase of depth, the better connectivity of sand body, the better migration performance of sand body. According to the basic types of sand body macro-connection, three types of sand connection patterns are established, i.e. thick sand body direct connection, micro fault connection, and thin or poor physical property sand body connection, and the migration performance evaluation plan of sand bodies in middle-shallow layers was provided.