Sedimentary evolution of Fuyu Oil layer in 401 block, Sanzhao Depression, Songliao Basin

Abstract

This paper takes Sanzhao Depression in Songliao Basin as the research target. Fuyu oil layer is in the 4th member of Quantou formation, Lower Cretaceous. The target layer in research area is mainly a set of shallow-water delta deposition, experienced the sedimentary evolution process from Delta plain to Delta front, reflect the water level changed from deep to shallow and back to deep. Because of the distributary channel frequently swing, single sand body thin thickness, study of micro facies must be carried out to guide further petroleum development. In the case of lack of core data, this study take advantage of seismic and logging data to analysis the micro facies of each reservoir group and sedimentary evolution of Fuyu oil layer. This paper proposes: 1. FⅢ, F Ⅱ, FⅠ3 and FⅠ2 sub-layer of Fuyu oil layer in research area is mainly Delta plain deposition; FⅠ 1 sub-layer is mainly Delta front deposition. 2. During the sedimentary period of FⅢ, FⅡ and FⅠ 3 sub-layer, the climate changed from humid to dry, sediment supply gradually increased; During the sedimentary period of FⅠ2 and FⅠ1 sub-layer, the climate changed from dry to humid, sediment supply gradually decreased.