The Structural Evolution and Petroleum Geologic Implication of Baiyinchagan Sag in Erlian Basin

The Baiyinchagan sag is a secondary structural unit of Erlian basin.Based on a lot of geologic,seismic and drilling data,this paper presents the structural and sedimentary evolution history of it and makes a classification of five stages by which its structural framework and sedimentary characteristic are controlled.In Bayanhua group of the Lower Cretaceous in this sag there exist 3 sets of source rocks and 2 sets of reservoirs.They are connective in plane and overlapped in vertical,thus providing good conditions for petroleum secondary migration and accumulation here.