Formation Conditions and Distribution Law of Tight Oil in Fuyu Oil Layer, Sanzhao Area, Songliao Basin

Abstract

The tight oil in the Fuyu oil layer in Sanzhao area of the Songliao Basin has huge resource and reserves, and has a good geological background for tight oil accumulation. It is the main direction of oil and gas exploration in recent years. The conditions and distribution rules of tight oil in Fuyu oil layer in Sanzhao area of Songliao Basin are analyzed by comprehensively using the data of geology, drilling, logging and geochemistry. The results indicate that there’s four favorable conditions for the formation of tight oil in study area: ①The crude oil has great properties and fluidity, and the formation conditions of tight oil are superior; ②The widely distributed high-quality source rock is close to the tight reservoir, that provides sufficient oil basis for the tight oil formation; ③The tight reservoirs distributed widely in a large area provide effective reservoir space for the tight reservoirs formation; ④Formation overpressure is organically matched with oil source faults, which offers sufficient power for tight oil to move downward. Finally, this article points out that the tight oil in Fuyu reservoir of Sanzhao area has the characteristics of large-area continuous distribution, strong heterogeneity, local "dessert" enrichment area, and the river sand body controls the local "dessert" enrichment area of tight oil.