Hydrocarbon enrichment rules of depression period layer in Changling region of southern Songliao Basin

Based on the research of structure, and sediment, favorable reservoir was predicted from the point of sequence controls sand and sedimentary microfacies control reservoir. Combined with analysis of hydrocarbon accumulation condition, rules of depression layer hydrocarbon enrichment in Changling region of southern Songliao Basin were discussed. The results show that cycle controls the place where hydrocarbon accumulates and valuable oil-bearing stratum are near the mature source rocks. Sedimentary facies control the place where favorable reservoir develops. The main oil-bearing areas distribute zonationally in delta front and shore lake crossover region. Underwater distributary channel and mouth bar are beneficial reservoir facies because there are more and better oil and gas. Basal fault zone is closely linked with favorable hydrocarbon accumulation areas. Oil-bearing areas are mainly controlled and influenced by the inherited basement fault. Hydrocarbon accumulation is closely related to strata distribution patterns and trap types. There are low-amplitude structural traps developed in the central flat area. Lithologic traps that are updip pinchout and structural lithologic traps are in the eastern inversion area. And there are low-amplitude structural traps and structural lithologic traps on the upthrow side of west faults in western slopes.