The formation conditions and prediction methods of near-source sand body adjacent to low salient in Bohai Bay Basin——taking Es1 and Es2 formation in the JZ-A structure, Liaodong Bay as an example

For a long time, because the area of low salient in Liaodong bay area in Bohai Sea was small, it wasn't considered as an effective source and the clastic reservoirs wasn't developed.By analyzing drilling and seismic data in JZ-A structure, braided valleys are developed in this low salient during sedimentation early stage of Es2 and they can be treated as the effective source.During late stage of Es2, the carbonate sediments were developed.Under the direction of dynamic source theory and based on the subtle analysis of palaeogeomorphology and paleovalley, braided-river delta distribution during early stage of Es2 was predicted by using seismic facies analysis techniques, seismic attribute analysis techniques and multi-attribute combination of cluster analysis techniques.Finally, a middle scale oilfield was found which provided reference for future petroleum geological exploration in other similar structures.