Abstract:  In order to ensure the hydrocarbon enrichment regularities and favorable exploration direction within the 4th Member of Quantou Formation in Wangfu area, seismic, geological, geochemistry, and testing data are used to analyze the main controlling factors and hydrocarbon accumulation mode of conventional and unconventional oil on the basis of reservoir classification and its distribution. There are two kinds of reservoirs in Wangfu area, conventional low-permeability reservoir and unconventional tight oil, and they are in order distribution. The hydrocarbon accumulations in the 4th Member of Quantou Formation are controlled by source rock, structure, fault, and reservoir. The distribution of low-permeability reservoir is controlled by strong hydrocarbon expulsion mudstone, while residual pressure is the main power for tight oil. The structure of the 4th Member of Quantou Formation is almost complete before the hydrocarbon expulsion, and north uplift with a low fluid potential is the target area for low-permeability reservoir migration. The open faults in NW direction are favorable channels for low-permeability reservoir migration in lateral and tight oil in vertical. Relatively high reservoir quality is the key factor of tight oil accumulation and low-permeability reservoir productivity. We recognized four kinds of accumulation modes in Wangfu area, such as “overpressure drive, vertical migration and enrichment in sweet points” within the deep depression, “fluid potential drive, lateral migration along the open fault and assemble in ancient culmination” among north uplift, “reservoir and source butt to butt, overpressure and fluid potential relay drive, fault and sandstone migrate together” in west steep slope, and “overpressure and fluid potential drive, sandstone migration and enrichment in sweet points” around gentle slope in the east.

Key words: low-permeability sandstone oil, tight oil, controlling factor; , the ,  4th Member of Quantou Formation, Wangfu area, Songliao basin