Abstract:

The main oil and gas exploration and development target in the Songliao Basin is the large fluvial channel sandstones or delta distributary channel sandstones. The singlelayer thickness of sandstone was small, the rivers diverted frequently, and characteristics of the stratigraphic correlation of channel were not obvious. Using seismic data to describe channel sandbody, recently we have developed a broad band high resolution seismic technology, so seismic predominant frequency bandwidth in Xingshugang of Songliao Basin has increased from 580Hz to 5360 Hz, seismic apparent dominant frequency is 150 Hz, and seismic resolution increases dramatically. It is an urgent task how to describe the sequence stratigraphy of channel sandbody using broad bandwidth high resolution seismic data. With forward modeling technology, we analyzed the thin layer channel sandbody characteristics on broadspectralbandwidth high resolution seismic. We realized that the inclined reflection of angular unconformity in both sides of channel sandbody is the important sequence stratigraphic logo for identifying channel sandbody. Combined with exploration well material, to explain broad bandwidth high resolution seismic profile in Xingshugang of Songliao Basin, we obtain some understanding. We found two sandbody types, i.e., the single channel sandbody and the composite sandbody. We analyzed the sequence characteristic of Fuyu reservoir on broad bandwidth high resolution seismic section. Through the channel sandbody profile feature analysis of x70 well, we know that the channel sandbody characteristics in Fuyu oil layer sequence five is anastomosing river delta.

Key words: sequence stratigraphy, channel sandstone, angle unconformable, high resolution seismic, Songliao Basin