Abstract: Based on the accumulation of previous research on deep strata and the progress of oil-gas prospecting in northern Songliao basin and its surrounding areas in recent years, this paper first introduced the characteristics of regional geology and geophysical fields, and then according to the features of the target stratum of deep strata, studied the structural and stratigraphic characteristics of the deep strata in the northwest Songliao basin by comprehensive geophysical prospecting methods such as broadband seismic and wide-field electromagnetic method. The petrophysical parameters of Songliao basin and its surrounding areas were sorted out, and the physical characteristics of strata with different formation ages were summarized, with emphasis on the analysis of the physical differences between the Upper Paleozoic and its upper and lower strata. It is concluded that there are obvious differences in physical properties between the Permian and its overlying Meso-Cenozoic, the underlying strata and various types of rocks in this area, which is the precondition to study the distribution of the Upper Paleozoic by geophysical methods. On this basis, this paper expounds the progress of combined geophysical investigation of gravity, magnetism, electricity and seismic in the key target area. The quality of broadband seismic imaging for the deep strata is significantly improved compared with the previous seismic explorations, and we have obtained clearer geophysical information. According to the above geophysical information, several geological survey wells were deployed, and successively drilled into the argillaceous rocks with anomaly of gas logging in deep Permian. In addition, this paper also discussed the challenges faced by the deep hydrocarbon geological survey and the future research directions in the study of petrophysical properties and integrated geophysical prospecting methods.

Key words: Songliao basin and its surrounding areas, deep Upper Paleozoic, petrophysical characteristics, integrated geophysical prospecting, broadband seismic, wide field electromagnetic method