Characteristics and Main Controls for Deep Hydrocarbon Accumulation in the South Slope of Dongying Depression

Key words: 
• origin type of oil /
• poolforming characteristics /
• main controlling factors /
• Wangjiagang area

Abstract:  The oil and source rocks correlation shows that the crude oil in this region can be classified into three types. Sources of oil in different horizons vary greatly, the first type crude oil which distributed in the deep reservoirs(Ek2-4１) in Kongdian Formation and Wanggu 1 well's Ordovician buried hill reservoirs in the north of Wangjiagang area, and the oil was mainly generated by the source rocks of Kongdian Formation(Ek); the second type oil has geochemiacal features of both the 4th member of Shahejie Formation(Es4) and Ek source rocks in Niuzhuang sag, it was mainly accumulated in the shallow reservoirs(Ek1,2１) in Kongdian Formation, and the third type oil which mainly sourced from the upper Es4 source rocks, always accumulated in the reservoirs of Shahejie Formation .According to the analysis of reservoirforming conditions, it can be seen that the Dingjiawuzi tectonic belt was of good hydrocarbon source conditions; Faults sandbodies and unconformities which formed the complex solid network paths. The reservoirs of sandstones and unconformities were the main pathway of oil and gas lateral migration, faults played diverting, gathering and connecting role. Dingjiawuzi nose-structural belt geological setting, the favorable combination of hydrocarbon generation, migration, accumulation periods and movement stage of faults and the essential seal of faults are the critical factors for the Kongdian Formation hydrocarbon accumulation in Wangjiagang area.