Abstract:Detailed seismic exploration which mainly aims at subtle reservoirs in the Biyang seg has been done since late 1980's. Controlled by different geological conditions in different areas, the subtle reservoirs occur in obvious regional distribution. Unconformable reservoirs are mainly discovered in the north slope (there are less fault nose and fault block reservoirs), sandy updip pinch-out and sand lens reservoirs are mainly in deep mid seg, and small structural reservoirs created by differential compaction occur in steep south slope. Different seismic exploration methods are used in different areas which have their distinctive geological conditions and reservoir types respecaively. The unconformable reservoirs in outside north slope can be discovered by using the seismic methods which protects shallow reflections, faulted nose and faulted block reservoirs in insde north slope by using three-dimensional seismic method, and stratigraphic and small structural reservoirs in mid-south seg by using high resolution three-dimensional seismic method. The above methods have brought quite good exploration results.