Structral Deformation And Hydrocarbon Accumulation Of Dehui Sag In Songliao Basin

Dehui sag is a secondary tectonic unit of the southeastern uplift of the Songliao Basin,controlled by the Dehui west fault and the Dehui east fault,forming an asymmetric graben structure.The Dehui sag can be divided into three tectonic belts from west to east,followed by the Longwang-Nong'an depression,the central convex belt and the eastern depression(the Baojia depression and the fault zone).The whole show a two-The geological structure of the characteristics.Based on the theory of modern tectonic geology,the tectonic analysis of Dehui sag is carried out by means of seismic interpretation,equilibrium profile,tectonic analysis and so on.Get the following understanding:The Dehui sag is located in the middle and west of the southeastern uplift of the Songliao Basin,with NNE spreading as a whole and the geological structure is asymmetrical double graben.According to the main rupture activities in the study area,the depression is divided into three sub-tectonic belts,from west to east,followed by the Longwang-Nong'an depression,the central convex belt,the eastern trough belt(Baojia depression)The two main faults,such as extensional and strike-slip faults,Dehui east fault and Dehui west fault,are mainly developed as two main control faults,which play an important role in the development of sediments and stratigraphic sediments.Which is the main basis for the division of tectonic zones in the study area.In the Mesozoic period,the Dehui sag experienced four stages of initial fault,strong fault,partial slip,and depression.The main sedimentary strata in the fault is the Jurassic Huoshiling Formation,the Cretaceous Shahezi Formation,the Denglouhu Formation,the local slippery period is the Yingcheng Formation,and the depression period is the Quantou Formation.Through the analysis of the reservoir cover in the study area,the reservoir model of lithologic tectonic reservoirs was established.