Abstract:

Based on geologic, drilling borehole and geochemical data from the Yushulin oilfield, the source rock in this area is
characterized by high organic matter abundance and hydrocarbon generation potential. Oil-source correlation shows that the oil
within the Putaohua reservoir is mostly originated from the first member of the Qingshankou Formation. Reservoir sandstones
is deposited in distributary channel environment of shallow-water delta, which can be defined as medium porosity and medium
permeability reservoirs. The reservoir types in this area are mainly controlled by lithology. From southwest to northeast in a plane,
the number of reservoir increases while the number of water layer decreases. In a vertical plane, the reservoir in the southwest
area is rich of oil, in the northeast rich of water, while in the middle area, water is rich at the bottom layer and oil is rich at the top
layer. Our study shows that the area with high maturity of source rock, effective reservoirs, active faults in the time of hydrocarbon
generation is favourable for hydrocarbon accumulation, which control the behavior of the Putaohua oil reservoir.

Key words: hydrocarbon accumulation；Putaohua oil reservoir, Yaojia Formation, Yushulin Oilfield, Songliao Basin