Fault Characteristics Of Shenxian Sag In Jizhong Depression And Its Control On Hydrocarbon Accumulation Conditions In Buried-hill

Buried hills in Jizhong depression are rich in oil and gas resources and there is still great exploration potential in Shenxian sag and Sunhu area in the south of Jizhong depression.The fault system in this area is rich in development,which affects the hydrocarbon accumulation in buried-hill in many aspects,but the structure is difficult to be realized due to the influence of seismic data accuracy and other factors.Understanding,in order to study the fracture characteristics of buried hill fracture control action of hydrocarbon accumulation conditions,this article obtains from the background of bohai bay basin,which is based on the dense seismic section,a detailed analysis of characteristics of fracture development in the study area,especially the main accused of buried hill fracture geometric elements and analyze the fault combination tectonic style and its effects on buried hill form.On this basis,the types of buried-hills are classified,and the buried-hills in Shenxian sag and Sunhu area are summarized as high slope warping buried hill,high slope horst buried hill,low slope warping buried hill and steep slope warping buried hill in combination with the formation reasons and their positions in the half graben.On the other hand,fault active periods were determined by using fault distance and buried depth curve and growth index,and the fault systems in the study area were divided into early active fault system,middle active fault system,late active fault system and long-term active fault system.The tectonic evolution history was compiled to analyze the process of fault formation and evolution and to discuss the control of different types of fault systems on the formation and evolution of buried hill.On the basis of above work,the analysis of buried hill fracture control action of hydrocarbon accumulation conditions,the study found that carbonate rock is influenced by tectonic movement,long exposure surface are formed by the dissolution of the larger pore volume of reservoir performance is good,because of the stress disturbance produced by fault activity produces a large number of cracks near the fault,also provide favorable conditions for oil and gas reservoir;The main fault activities lead to the formation of tilting action,and when the tilting amplitude is larger than the slope background,the same direction of fault trap can be formed in the footwall of the fault.When the formation length is the same,the larger the tilting amplitude is,the larger the trap size is.Fault is an important oil and gas migration channel and unconformity surface of deep buried hill reservoir of petroleum system in a typical county sag buried hill hydrocarbon accumulation process as an example,summarizes its role in the process of buried hill fracture reservoir,rich in the buried hill reservoir,the application of the theory of fracture control to provide reference for further research and,also continue to exploration of the buried hill reservoir in the study area have actual effect.