Study On The Genetic Relationship Of Different Strike Faults In Huimin Sag

Huimin sag is located in the west of Jiyang depression,which is rich in oil and gas resources.There are many faults in different directions in the sag.The typical blocks of these faults in different directions are Linbei,Panhe,Jiangjiadian and Qudi.It is of great significance to clarify the combination patterns,interrelationships and genetic evolution of these faults in different directions for the exploration and development of oil and gas in the sag.Based on the relevant theoretical methods of basin structure analysis and oil area structure analysis,this paper explains and analyzes the existing geological data and two-dimensional and three-dimensional seismic data,and draws the following understanding.According to the fault strike,the faults in the Huimin sag can be roughly divided into three categories: NE-trending,nearly east-west-trending and nearly north-south-trending.Among them,most of the NE-trending faults are the main large faults in the sag,and most of the nearly east-west-trending faults and nearly north-south-trending faults are low-grade faults in the sag.According to the interpretation results of geological data and seismic data,the faults in Huimin sag are mainly extensional,and some faults have strike-slip properties.The combination patterns of faults on the section are mainly listric fan,ladder,Y-shaped,conjugate,oblique and flower-like.The combination patterns of faults on the plane are mainly horsetail,feather,radial,conjugate,vertical and parallel.According to the calculation results of fault activity,the NE-trending faults in Huimin Sag are mainly active in the sedimentary period of Kongdian Formation and the sedimentary period of the fourth member of Shahejie Formation.There is a slight difference between the near east-west fault and the near north-south fault in the specific period of fault activity in different blocks,but most of these small faults begin to be active in the sedimentary period of the third member of Shahejie Formation.According to the analysis results of the mechanical mechanism,the NE-trending faults in the Huimin sag are caused by the extension of the north-south-east direction.The near-east-west faults are mainly caused by the extension of the north-south direction.The development of the near-north-south faults is affected by the near-east-west fault activity.At the same time,it is also affected by the basement arching,fault block tilting and NE-trending fault strike-slip activity.According to the different development positions,the causes of these faults in different directions are also different,but the activities of these faults are affected by strike-slip.