摘要：Recently, an important development trend of oil and gas exploration extends to the deep part of the basin. At present, the oil and gas exploration in the Songliao Basin is still located in the mid-deep layer, and the deep reservoir of the first and second members of the Quantou Formation (K_(1q)), which is the focus of oil and gas exploration. In particular, there is no clear understanding of the deposition system, which also limits the further exploration and development of the deep reservoir. Based on the analysis of heavy mineral assemblage and formation sand ratio, provenance of five tectonic zones in the first and second member of Quantou Formation are identified. Sedimentary system of the first and second members of the Quantou Formation in the northern part of the Songliao Basin is discussed based on drilling data and logging curve. Results show that the first and second members of Quantou Formation are mainly composed of five significant sedimentary facies including meandering river facies, braided river facies, alluvial fan facies, delta facies and shallow lake with characteristics of 'steep slopes into a fan, gentle slope into the river'. Sedimentary facies are further subdivided into eleven sub-facies and characteristics of the sedimentary system, and the spatial arrangement is identified combined with the current exploration practice. On this basis, the distribution characteristics of the sedimentary system and the spatial configuration of the "steep slope type-gentle slope type-straight type " are figured out.
