Application of sequence stratigraphy to exploring the subtle traps of Damoguaihe formation in the north of the Wuerxun depression
层序地层学在乌尔逊凹陷北部大磨拐河组隐蔽油气藏勘探中的应用

The study of subtle Traps based on the high-resolution seismic data is a focused subject in hydrocarbon exploration. Based on the theory of sequence stratigraphy, and comprehensive using of the logging and sedimentology, the favorable parts can be identified. This paper deals with the theoretical basis and working process of sequence stratigraphy and has applied it to the rift lacustrine basin to find the subtle traps of Damoguaihe Formation in the north of the Wuerxun depression in the Hailaer Basin. The formation of interest is a whole second-order sequence and consists of low stand system tracts (LST), transgressive system tracts (TST) and highstand system tracts(HST). It is suggested that the main reservoir is sublacustrine fan developed in the f lowstand system tracts (LST) and the lithology updip pinchout reservoir developed in the slope break zones.