Abstract: Well-seismic integrated reservoir characterization of Daqing Changyuan oilfield at late high water cut development stage faces the challenges of small scale of description target,high requirement for predication accuracy and dense well pattern.Taking Block X56 of Xingshugang oilfield in the Songliao Basin as an example,we developed a set of technologies consisting of well-seismic integrated structure interpretation,fault identification and reservoir prediction by utilizing 3D seismic data and fine geologic study results.The capacity-dimension fractal technology is applied to recognize small faults with throw of about 5 m,solving problems of small faults identification between wells.The plane combination characteristics and extensions of faults are defined and the relationship between low amplitude structure and oil-gas distribution is determined by using well-seismic integrated structure interpretation technology.Reservoir sandbody thickness in the 1^st member of Putaohua Formation is mapped and the sandbody connectivity between wells is analyzed with the stochastic inversion technology.The coincidence rate of prediction of sandbodies with thicknes above 2 meters is more than 75%.On this basis,sedimentary microfacies map drawn only by borehole data is further revised,and the planar distribution features of channel sandbody are characterized.The well-seismic integrated 3D seismic interpretation technology has been applied in several blocks of Changyuan oilfield and the results are satisfactory.

Key words: fault, structure, sedimentary microfacies, 3D seismic interpretation technology, reservoir description, Songliao Basin