Structural evolution characteristics of Shuangcheng area and its control effect on oil and gas accumulation

In order to effectively understand the control effect of structural evolution in the process of oil and gas accumulation in Shuangcheng area,new 3 D seismic data were used to analyze fault characteristics and typical structures,study the formation mechanism,discuss the matching relationship between structural formation period and reservoir forming period,and clarify the exploration direction.The results show that the Shuangcheng area has experienced three stages of transformation:compression at the end of Yingcheng formation,strike slip at the end of Quantou formation and uplift at the end of Nenjiang formation.Among them,in the end of Quantou formation the strike-slip effect is great for the study area,a series of left-lateral strikeslip structures were formed,and conjugate fractures were formed in NNE direction and NW direction.There are different secondary stresses in different directions within the strike slip structural belt,forming a series of strike slip associated structures with different properties of tension and compression.The NNE direction faults have compressive stress properties and their associated structures are positive,while the NW direction faults have tensional stress properties and their associated structures are negative.Through thermal history simulation,Shuangcheng area entered the peak period of hydrocarbon generation at the end of Qingshankou formation,later than the left lateral structural formation period of Quantou formation.Combined with the structural properties and reservoir forming conditions,three NNE trending structural belts were identified as the key exploration direction in the near future.