青东凹陷新生代构造应力场特征及其与油气运聚的关系

fter using two dimension finite element method to implement numerical simulation on the cenozoic paleo-tectonic stress field of Qingdong Sag, the difference and space distribution regularity of tectonic stress field in Cenozoic different geological history stages were analyzed. Furthermore, the relationship between the tectonic stress field characteristics and hydrocarbon migration was discussed. The result showed that in Kongdian and the lower forth stage of the Shahejie period, Qingdong Sag was located in N(N)W~S(S)E tensional stress field, the strikes of the main faults were NW and EW. Tanlu fault sinistral strike slip was weak and the tension effect was stronger than that of the strike slip. During the above period Qingdong, Sag experienced structural transformation. From the upper forth stage to the second stage of the Shahejie period, Qingdong Sag was located in N(N)W~S(S)E tensional stress field. Tanlu fault became dextral strike slip and the strike slip and tension were both strong. During the first stage of the Shahejie and Dongying period, Qingdong Sag was located in dextral shear stress field and the regional tension of the basin became weaker. At the end of Dongying period, Qingdong Sag was located in dextral compressive tectonic stress field, Tanlu fault transformed from dextral tension into dextral compression. Between the Guantao to the Minghuazhen period, the dextral shear and tension of the Tanlu fault became weak. Under the NNW-SSE major principal stress, within the key period of hydrocarbon accumulation, the favorable hydrocarbon zones of Qingdong Sag generated oil and gas and then migrated respectively towards west slope zone, transitional zone and east strike slip belt. And now the hydrocarbon favorable accumulation zones of Qingdong Sag is in the low tension value and high shear stress value zone of the minimum principal stress.